Abstract
Sustainable, sulfonated mesoporous SBA-16 catalysts were synthesized from sugarcane bagasse ash (SCBA), an abundant agro-industrial waste from bio-energy production. SBA-16 modification with 3-mercaptopropyltrimethoxysilane (MPTMS) and subsequent oxidation to incorporate sulfonic acid groups, significantly enhanced the textural properties, achieving a surface area of 207 m2/g, while trace impurities from SCBA may enhance Lewis acidity. Such features improved catalytic efficiency and sustainability. A green assessment of catalyst synthesis from SCBA using the DOZN™ Green Chemistry Evaluator revealed that the SCBA-based methods are more sustainable than conventional TEOS-based methods. This study represents the first application of sulfonated SBA-16 for Biginelli reactions, yielding 99% for the reaction between benzaldehyde, methyl acetoacetate, and urea (at 105 °C, 7 h, 10 wt% catalyst, in ethanol). Catalysts demonstrated exceptional durability, with negligible loss of activity (~ 98%) over five consecutive cycles, highlighting its suitability for this application. SBA-16 catalysts exhibited broad substrate compatibility, particularly with electron-withdrawing groups across various aldehydes and β-diketones. The Biginelli reactions aligned with green chemistry principles, achieving favorable values for process mass intensity (PMI: 11.86–33.32 g/g), E-factor (10.86–32.32 g/g), solvent intensity (SI: 9.69–14.50 g/g), and water intensity (WI: 3.28–9.36 g/g). The Green Motion sustainability assessment tool score was 75/100. Sulfonated SBA-16 catalysts offer a sustainable alternative to commercial silica, with superior performance, reduced catalyst loading, and minimized environmental impact, underscoring its potential for use in industrial applications.
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Introduction
Currently, industries are dependent on fossil resources for fuels1,2. However, such resources are rapidly depleting due to rising consumption and population growth and as such their value has increased dramatically3,4,5. While they can regenerate naturally, this process spans millions of years and is unsustainable. Moreover, reliance on fossil resources significantly contributes to carbon dioxide emissions, potentially driving global warming6,7. To address these challenges, it is crucial to identify sustainable alternatives to replace dwindling fossil resources, such as biomass or agro-industrial waste.
Sugarcane bagasse is on such waste that can be utilized for energy, chemicals or materials production. In 2020, approximately 115 countries produced over 1.9 billion tons of sugarcane, largely for sugar, paper, and alcohol production8. Thailand, the largest sugar producer in East Asia9, generates substantial quantities of bagasse during sugar extraction. Bagasse, comprising about 27–30% of the fresh sugarcane’s weight, is often burned to generate electricity, leaving an ash as waste. This bagasse ash is typically discarded, adding cost and potentially causing environmental issues10,11,12. To reduce these impacts, researchers are exploring methods to convert bagasse ash into valuable materials rather than disposing of it13,14. A promising solution is to transform sugarcane bagasse ash into advanced materials, thereby increasing the value of the waste, whilst reducing its environmental burden. Since sugarcane bagasse ash predominantly contains silicon dioxide (SiO2), it can serve as a as a precursor for the production of mesoporous silicas and potentially as catalysts for use in chemical synthesis. Using ash as a catalyst precursor can minimize environmental impact, supporting a circular economy. However, developing catalyst systems from these waste-derived materials still presents challenges, such as ensuring efficient recovery and practical reuse of the newly formed catalysts.
Among the most intriguing classes of organic transformations are multicomponent reactions (MCRs), which generate a single product from three or more starting materials in a single step15. A prominent example of an MCR is the Biginelli reaction, involving the condensation of urea, an aldehyde, and a β-ketoester to produce dihydropyrimidones (DHPMs)16. The interest in this reaction has grown substantially due to the broad spectrum of biological activities associated with DHPMs, including antiviral, antibacterial, antifungal, antioxidant, and anti-inflammatory properties17,18,19,20. Over the years, a variety of catalysts have been employed for the Biginelli reaction, ranging from homogeneous acids (e.g., HCl21, HClO422, NH4Cl23, H2SO424) to heterogeneous catalysts (e.g., Al2O3-SO3H25, Si-MCM-41 supported metal halides26, PEG-SO3H27, and ZrO2 nanopowder28). Heteropoly Acids (HPAs), such as Keggin-type H3PW12O40 and H4SiW12O40, have also gained attention for their strong Brønsted acidity and high catalytic efficiency. However, challenges remain, such as extended reaction times, harsh reaction conditions, the use of organic solvents, and difficulties in catalyst recovery29. For example, Al2O3-SO3H catalysts may suffer from leaching of sulfonic acid groups, while Si-MCM-41-supported metal halides can deactivate due to metal halide leaching and pore blockage. Similarly, PEG-SO3H exhibits limited reusability because of its solubility in certain solvents, and ZrO2 nanopowders may experience deactivation caused by surface phase changes or loss of surface area. HPAs, despite their high efficiency, may face reusability issues due to their solubility in polar solvents, leading to efforts to immobilize them on solid supports for improved stability and recyclability. Homogeneous catalysts, in particular, pose issues related to separation, recyclability, and corrosion. To overcome these limitations, the development of solid catalysts offers a promising alternative. Solid catalysts are easier to separate and reuse, reducing waste and enhancing sustainability. By alleviating the disadvantages associated with homogeneous catalysts, these solid catalysts pave the way for more environmentally friendly and resource-efficient chemical processes.
Solid acid catalysts, in particular, offer numerous advantages, such as high performance, ease of handling, convenient recycling, are non-corrosive, and can reduce environmental impact, these attributes that are vital for advancing clean technologies in this field. A variety of silica-based catalysts have been reported in the literature, including Si-MCM-41 supported metal halides30, silica/Fe31, silica sulfuric acid32, SiO2/ZnCl233, silica-SO3H34,35,36, Si(OEt)4/FeCl337, silica-chloride38, silica-triflate32, SAP-37ZR39 and SiO2–Si(CH2)3SO3H40. While these catalysts demonstrate excellent performance, they often require complex preparation methods, long production times, are resource intensive and may cause other environmental concerns41. In contrast, using sugarcane bagasse ash as a feedstock for the synthesis of mesoporous silica supports for catalysts offers several key advantages, including utilize waste residues and reduce environmental impact.
Porous materials with specific structures, such as zeolites and mesoporous materials, have been extensively studied for their catalytic properties due to their precise control and tunable characteristics. These materials, with high surface areas and adjustable pore sizes, are particularly effective in shape-selective catalysis, allowing for efficient reactions by distinguishing molecules based on their shape and size42. Santa Barbara Amorphous (SBA) refers to a family of mesoporous silica materials known for their large pore sizes, thick walls, and high thermal stability. These materials are typically synthesized using neutral block copolymer templates43. Common members of this family include SBA-1, SBA-3, SBA-15, and SBA-1644. Among these, SBA-15 features a two-dimensional hexagonal structure, while SBA-16 has a three-dimensional cubic arrangement (Im3m) of cage-like pores. SBA-15 consists of cylindrical pores with uniform sizes, whereas SBA-16’s pore network is composed of spherical pores interconnected by smaller channels45. The distinct and accessible pore structure of SBA-16 makes it particularly attractive for catalytic applications, due to its good thermal stability, cost-effective synthesis, and three-dimensional porous framework46. Functionalized SBA-16 has been applied in various domains, including catalysis47, environmental studies48, and electronics49. Despite its potential, SBA-16 remains less extensively explored than other SBA materials, primarily due to the specific and controlled conditions required for its synthesis50. There have been some reports on the use of functionalized SBA-16 as a catalyst in multicomponent reactions. For instance, Boza et al.51 developed a mesoporous material using SCBA as the silica source and functionalized it with sulfonic acid groups to create an acid catalyst, SBA-16/SO3H. The catalytic activities of SBA-16 and SBA-16/SO3H were evaluated in Kabachnik–Fields reactions for the synthesis of α-aminophosphonate compounds. The results indicated that both catalysts show promise, with SBA-16/SO3H demonstrating slightly superior performance. However, this reaction requires hazardous solvents, such as dichloromethane, which limits its environmental compatibility. Similarly, Maheswari et al.52 reported the synthesis of mesostructured Zr-SBA-16 using tetraethyl orthosilicate (TEOS) as the silica source. This material proved to be an efficient Lewis acidic catalyst for the Hantzsch reaction. However, the use of TEOS poses a challenge due to its toxicity and associated health risks53. Furthermore, Gupta et al.54 described the synthesis of 2-iminothiazolidin-4-ones using a guanine-functionalized SBA-16 catalyst (SBA-16@G). This heterogeneous solid base catalyst efficiently facilitated the reaction of aromatic/aliphatic amines, aryl isothiocyanates, and ethyl bromoacetate and was shown to be recyclable. However, drawbacks remain, including the reliance on TEOS as the silica source and the complexity of the synthesis process, which involves dry solvents such as toluene and dichloromethane (DCM). Additionally, the multicomponent reaction requires the use of toxic solvents like dimethylformamide (DMF), and the catalyst’s reactivity decreases after four cycles, with yields dropping from 92 to 81%. As such, using inexpensive silica sources instead of costly alternatives like tetraethyl orthosilicate (TEOS), combined with a straightforward synthesis process, represents a significant advancement for the industrial-scale production of mesoporous materials. This approach enhances the durability and stability of the resulting materials, making it a practical and cost-effective solution for large-scale applications.
This study investigates the development of sulfonated mesoporous SBA-16 catalysts from SCBA and for the first time its application as a catalyst in the Biginelli reaction. By optimizing the reaction conditions, an effective and sustainable process for synthesizing dihydropyrimidones has been developed. In addition, the exploration of substrate scopes and evaluated the catalyst’s recovery and reusability. The Biginelli reaction was further assessed using green chemistry metrics, underscoring the environmental advantages of this approach. In addition, the environmental impact of sulfonated mesoporous SBA-16 catalyst synthesis was assessed using the green metrics methodology, evaluating its impact on the 12 Green Chemistry Principles (GCPs). Overall, employing a catalyst derived from waste not only broadens the scope of multicomponent reactions but also offers a sustainable, eco-friendly, and cost-effective organic synthesis.
Experimental section
Materials and methods
Sugarcane bagasse ash (SCBA) was sourced from Buriram Energy Co., Ltd. (BEC), a biomass power plant located in Buriram province, Thailand. All reagents and solvents were used as received from commercial suppliers without further purification. X-ray diffraction (XRD) patterns were recorded on a Bruker/D8 Advance diffractometer using a Cu Kα radiation source (40 kV, 40 mA). Low-angle XRD patterns were obtained with the same instrument, utilizing Cu Kα radiation (λ = 1.5406 Å) and operating at 40 kV and 40 mA, with a step time of 0.1 s over a range of 0.5° < 2θ < 10°. Nitrogen adsorption–desorption isotherms were measured using a Micromeritics/TriStar II Plus analyzer. Specific surface area was calculated using the Brunauer–Emmett–Teller (BET) method, while pore size distribution was determined using the Barrett–Joyner–Halenda (BJH) method. Thermogravimetric analysis (TGA) was conducted on an SDT Q600 thermal analyzer (TA Instruments, New Castle, DE, USA). Samples were heated from 50 to 800 °C at a rate of 20 °C/min under a nitrogen atmosphere. Fourier-transform infrared (FTIR) spectra were collected on a Bruker/INVENIO-S spectrometer within the range of 400–4000 cm−1. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) images were captured using a JEOL/JSM-6010LV microscope, while Transmission Electron Microscopy (TEM) images were obtained with an FEI/TECNAI G2 20 microscope. 1H Nuclear Magnetic Resonance (1H NMR) spectra were recorded on a Bruker/Ascend-400 spectrometer (Prodigy unit) operating at 400 MHz, using DMSO-d6 as the solvent. Chemical shifts (δ) are reported in parts per million (ppm) and coupling constants (J) are expressed in Hertz (Hz).
Catalyst synthesis
Synthesis of SBA-16
First, SCBA was utilized as the silica precursor for synthesizing SBA-16. The synthesis process was based on a previously reported method with slight modifications51. Specifically, 4.0 g of SCBA and 6.0 g of NaOH (in a 1.5:1 w/w ratio) were combined to form a homogeneous blend. This mixture was heated in a crucible at atmospheric pressure at 550 °C for 40 min. The resulting fused material was then dissolved in 50 mL of deionized water, yielding solution 1. Separately, 4.0 g of the surfactant Pluronic F127 were dissolved in 120 mL of 2 M HCl at room temperature, and the mixture was stirred until a homogeneous gel (solution 2) formed. Solution 2 was gradually added to solution 1, and the combined mixture was stirred moderately at room temperature for 20 h. The resulting solid product was filtered, washed with deionized water, and air-dried at 80 °C for 4 h. Finally, the dried product was calcined in air at 550 °C for 6 h to remove the surfactant, yielding the final product, designated as SBA-16 (Fig. 1).
A step-by-step diagram illustrating the procedure for catalyst synthesis.
Synthesis of sulfonic acid functionalized SBA-16 (SBA-16/SO3H)
To functionalize SBA-16 with thiol (RSH) groups, a batch reaction was conducted in a 150 mL flask equipped with a stirrer, thermometer, and reflux condenser at 60 °C. In a typical procedure, 1.0 g of SBA-16 was dispersed in 30 mL of toluene, and 1.0 mL of 3-mercaptopropyltrimethoxysilane (MPTMS) was added. The mixture was stirred continuously for 24 h. The thiol-functionalized SBA-16 was then oxidized by slowly adding 30 mL of a 30 wt% H2O2 solution dropwise, with moderate stirring at room temperature, over 24 h. The resulting solid product was recovered by filtration, washed thoroughly with deionized water, and air-dried at 80 °C for 4 h. This product was designated as the SBA-16/SO3H catalyst (Fig. 1).
General procedure for the preparation of 3,4-dihydropyrimidin-2(1H)-ones
A mixture of aldehyde (5 mmol), β-ketoester or 1,3-diketone (7.5 mmol), urea (5 mmol), varying amounts of catalyst, and 4 mL of ethanol was stirred at different temperatures and durations. The reaction progress was monitored by thin-layer chromatography (TLC) using dichloromethane/methanol (9:1) as the eluent. Upon completion, the reaction mixture was filtered to recover the catalyst, and the filtrate was evaporated to obtain a solid product. The solid was washed with 10 mL of 50% aqueous ethanol and recrystallized from ethanol (5 mL) to yield a pure product. The recovered catalyst was washed twice with 10 mL of hot ethanol and reused in subsequent reactions.
Results and discussion
Catalyst characterization
X-ray diffraction (XRD) spectroscopy
The X-ray diffraction (XRD) patterns of sugarcane bagasse ash (SCBA) indicate that it is primarily composed of SiO2, along with minor components such as Al2O3, Fe2O3, K2O, and CaO. Silica in the form of quartz crystals is clearly identified by peaks at 21.1° and 26.9° 2θ (Fig. 2)55.
X-ray diffraction patterns of SCBA.
Figure 3 shows the small-angle X-ray diffraction (XRD) patterns of SBA-16 and SBA-16/SO3H. The results reveal that distinct diffraction peaks are absent for SBA-16/SO3H. In contrast, SBA-16 displays strong diffraction peaks at 2θ = 0.97°, 1.25°, 1.38°, and 1.76°, corresponding to the (110), (200), (211), and (220) crystal planes of the Im3m cubic structure, confirming the integrity of its cage-like mesoporous structure. These findings are consistent with previous studies56,57,58. For SBA-16/SO3H, a decrease in peak intensity is observed, attributed to the sulfonation process. The incorporation of SO3H groups into the mesoporous channels of SBA-16/SO3H causes this reduction in intensity. This aligns with prior research59,60, which confirmed the successful anchoring of SO3H groups onto the surface of SBA-16.
Small-angle X-ray diffraction patterns of SBA-16 and SBA-16/SO3H.
N2 adsorption–desorption isotherms
The BET analysis results for the mesoporous catalysts SBA-16 and SBA-16/SO3H, presented in Fig. 4, demonstrate that the synthesized catalysts are porous and exhibit type IV isotherms, characteristic of mesoporous materials as classified by IUPAC61. A distinct hysteresis loop was observed in the relative pressure range of P/P₀ = 0.42–0.98. Surface modification with –SO3H groups increased the catalyst’s surface area from 189 to 207 m2/g with the same pore size of 15.5 nm (Table 1). The low surface area (approximately 200 m2/g) of SBA-16 may result from impurities in sugarcane bagasse ash, such as carbon, may hinder the development of an ordered structure, leading to a reduced surface area. The use of a starting material with impurities and incomplete control over the self-assembly process are also factors contributing to the lower surface area of the SBA-16 compared to typical SBA-1662. These changes reflect an increase in nitrogen adsorption, indicating that the textural properties were altered by the modification process. The modification involved using 3-mercaptopropyl(trimethoxy)silane to functionalize SBA-16/SH, followed by oxidation to convert thiol groups into -SO3H groups (SBA-16/SO3H). The introduction of a significant number of -SO3H groups and chemical reactions between the silanol groups of silica and the methoxy groups of silanes account for the observed changes, consistent with the findings of Akopyan et al.63.
BET adsorption–desorption isotherm of SBA-16 and SBA-16/SO3H.
Thermal analysis
Thermogravimetric analysis (TGA) was used to evaluate the thermal stability of the catalysts before and after sulfonation (Fig. 5). The first weight loss observed around 100 °C in all the samples is due the moisture. For the sulfonated catalysts (SBA-16/SO3H and SBA-16-C/SO3H), the TGA-DTG curves showed a rapid weight loss between 200 and 600 °C, corresponding to the decomposition of sulfonic groups (-SO3H). This result confirms the successful incorporation of sulfonic groups onto the catalyst surfaces64. To maintain the efficiency of the sulfonic acid catalysts, catalytic processes should be conducted at temperatures below 200 °C to avoid thermal degradation. At higher temperatures (550–600 °C), the decomposition of CaCO3 and CaO was observed, as evident from the peaks in the TGA curves of SCBA and SBA-1665. This indicates the presence of residual inorganic components in the ash-derived catalysts.
TGA-DTG measurements for SCBA, SBA-16, and SBA-16/SO3H.
Fourier transform infrared (FT-IR) spectroscopy
Figure 6 illustrates the FTIR spectra of the samples, highlighting key functional groups. For SCBA, a broad band at 3348 cm−1 indicates the presence of hydroxyl groups (–OH). Peaks at 1654 cm−1 and 1432 cm−1 correspond to carbonyl (C=O) and alkene (C=C) group vibrations, respectively, while the C–OH stretching vibration at 1040 cm−1 is likely associated with cellulose. Peaks at approximately 457 cm−1 and 810 cm−1 are attributed to the vibrations of Si–O–Si bonds, consistent with previous studies66. In SBA-16 and SBA-16/SO3H, the peaks at 457 cm−1 and 810 cm−1 represent the symmetric stretching of Si–O–Si bonds, while a broad band in the 1300–1000 cm−1 range corresponds to the asymmetric stretching of Si–O–Si. The peak at 960 cm−1 is attributed to silanol groups (Si–OH), reflecting the material’s structural integrity. In SBA-16/SO3H, additional IR signals characteristic of sulfonic acid groups are observed: a peak at 920 cm−1 (S–O), 1420 cm−1 (S=O), and a broad band in the 3000–3250 cm−1 range (O–H), indicating the bending vibrations of strongly hydrogen-bonded –SO3H groups, consistent with previous findings54. The broad peak at 3348 cm−1 corresponds to residual absorbed water molecules and overlaps with the O–H bond stretching of silanol groups67. These peaks confirm the incorporation of sulfonic groups (–SO3H) into the mesoporous silica framework of SBA-16/SO3H.
FTIR spectrum of SCBA, SBA-16, and SBA-16/SO3H.
Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis
Figure 7a shows the SEM images of SCBA, revealing a diverse range of particle morphologies, including large, irregular tubular structures. The mesoporous silica SBA-16 (Fig. 7b) exhibits irregular crystalline morphologies, which are typical of such materials. In the SBA-16/SO3H catalyst (Fig. 7c), SEM images indicate that the primary morphology of SBA-16 changes following sulfonic group modification, with the SO3H-functionalized particles showing a tendency to aggregate68,69. This observation aligns with the findings from TGA, BET, and FTIR analyses, further confirming the successful incorporation of SO3H groups in SBA-16/SO3H.
SEM images of (a) SCBA, (b) SBA-16, and (c) SBA-16/SO3H.
Figure 8a–c presents the SEM–EDS maps of SCBA, SBA-16, and SBA-16/SO3H, highlighting the distribution of C, Si, O, and Ca elements in these samples. The presence of Ca in SCBA and SBA-16 is consistent with the XRD and TGA results, confirming that Ca is part of the material structure. The SEM–EDS maps also reveal a reduction in the amounts of C and Ca in SBA-16 and SBA-16/SO3H, which can be attributed to the calcination process during synthesis (Table 2). Furthermore, the maps confirm the presence of sulfur (S) in SBA-16/SO3H, indicating the successful incorporation of SO3H groups on the catalyst surface.
Elemental mapping images of (a) SCBA, (b) SBA-16, and (c) SBA-16/SO3H.
Transmission electron microscopy (TEM) analysis
The TEM images of SBA-16 (Fig. 9a,b) reveal an orderly mesoporous structure, consistent with previous studies70,71. This structure features spherical shapes indicative of a cubic Im3m arrangement of mesopores in a radial alignment. Such an arrangement reflects a well-ordered pore channel network with uniform pore distribution in a three-dimensional pattern. These observations are further supported by XRD analysis, which confirms the presence of a crystalline phase corresponding to the Im3m structure. Other studies72,73 have similarly emphasized the uniformity and orderly arrangement of SBA-16, confirming that the synthesized catalyst possesses the characteristic features of SBA-16 silica.
TEM images of the catalysts (a, b) SBA-16.
Sulfonic acid densities of the sulfonated catalyst
The acid density of the SO3H groups in the SBA-16/SO3H catalyst was determined using a standard acid–base titration method (Table 3). The calculated acid densities were 3.5 mol% for SBA-16/SO3H. This finding aligns with the sulfur content observed in the SEM–EDS analysis, the increase in surface area measured by BET, and the FTIR analysis discussed previously.
Catalyst performance evaluation
Catalyst screening
To broaden our screening of catalysts for the Biginelli reaction, the reaction was further investigated using aldehyde, methyl acetoacetate, and urea as starting materials under the following conditions: 10 wt% catalyst in 4 mL of ethanol at 75 °C for 3 h (Fig. 10). SBA-16 was subsequently modified by incorporating sulfonic (SO3H) groups into their frameworks, resulting in two catalyst samples (SBA-16 and SBA-16/SO3H). Among these catalysts, the SBA-16/SO3H synthesized by SCBA exhibited the higher performance, achieving about 71% yield (Table 4). The introduction of SO3H groups notably enhanced catalytic efficiency, confirming that SBA-16/SO3H prepared from SCBA is the most effective catalyst under these conditions. When compared with conc. H2SO4 at the same molar ratio (3.5 mol%), which gave a yield of approximately 70%, SBA-16/SO3H demonstrated comparable performance. This slightly improved efficiency is attributed to the incorporation of SO3H groups, which enhanced catalytic activity and provide better stability and recyclability compared to homogeneous catalysts like conc. H2SO4. Additionally, the higher catalytic activity of SBA-16/SO3H may also be due to the presence of other elements within the SBA-16 structure, which can further assist in promoting the catalytic process, enhancing its overall performance. Although the SBA-16/SO3H catalyst prepared from SCBA exhibited a relatively low surface area (~ 200 m2/g), it still showed high efficiency in promoting the Biginelli multicomponent reaction. This highlights its potential as a sustainable and effective alternative to traditional acid catalysts.
Scheme for multicomponent Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-one (DHPMs).
Optimization of the Biginelli reaction’s parameters
To determine the effect of temperature on the Biginelli reaction yield, experiments were conducted at temperatures ranging from 60 to 120 °C for 7 h, using a catalyst concentration of 10 wt% (Fig. 11a). All reactions were performed in triplicate, yielding a standard deviation of less than 0.5, which demonstrates the consistency and reliability of the experimental results. The yield increased steadily with rising temperature, from 47.25 at 60 °C to 98.58% at 105 °C. Beyond 105 °C, increasing the temperature to 120 °C only marginally improved the yield from 98.58 to 99.77%. Thus, 105 °C was identified as the optimal temperature. This improvement can be explained by higher temperatures enhancing reactant miscibility and collision frequency, ultimately increasing productivity75. In addition to temperature, the reaction duration significantly influenced the yield. As shown in Fig. 11b, the yield was 18.61% after the first 30 min and reached nearly 100% after 7 h, establishing 7 h as the optimal reaction time. Catalyst concentration also affected the yield (Fig. 11c). Increasing the catalyst amount from 1 to 10 wt% improved the yield from 35.37 to 98.58%. Beyond 10 wt%, further increases in catalyst concentration did not significantly affect the yield. Therefore, the optimal catalyst concentration is 10 wt%. In summary, the optimal conditions for the Biginelli reaction are a temperature of 105 °C, a reaction time of 7 h, and a catalyst concentration of 10 wt%.
Impact of various reaction parameters (a) Reaction temperatures, (b) Reaction times, and (c) Catalyst loading.
Substrate scopes
To broaden the scope of the Biginelli reaction, various aldehydes and β-diketonates were tested under optimized conditions, employing SBA-16/SO3H as the catalyst at a 10 wt% loading, 105 °C, and a reaction time of 7 h (Fig. 12 and Table 5). The results revealed that the electronic effects of substituents on the aromatic ring strongly influenced the reaction yield. Aldehydes bearing electron-withdrawing groups (e.g., 4e, 4j, and 4o) produced high yields (97%, 95%, and 96%, respectively), consistent with the findings of Firouzeh et al.76 In contrast, unsubstituted aldehydes (such as 4k) showed slightly lower yields (~ 91%), while those with electron-donating groups (e.g., 4l, 4g, and 4b) yielded less than 50%, in agreement with Zhen et al.77 Further comparisons indicate that SBA-16/SO3H generally provides yields equal to or superior to those previously reported for similar substrates (e.g., 4a, 4c, 4e, 4f, 4g, 4h, 4j, 4k, 4m, and 4o), and even surpasses them for some aldehydes (e.g., 4b, 4d, 4i, 4l, and 4n). This suggests that most aldehydes are compatible with the Biginelli reaction under these conditions, emphasizing the suitability of the SCBA-derived SBA-16/SO3H catalyst for efficient one-pot multicomponent syntheses.
Scheme for substrate scope for the Biginelli reaction in presence of SBA-16/SO3H under optimal condition.
Comparison of recently reported protocols for the optimized Biginelli reaction
To demonstrate the efficiency of the proposed Biginelli reaction the results of the current study were compared with various silica-based catalysts reported in the literature (Table 6). The preparation method of the sulfonated SBA-16 catalysts from SCBA avoids common drawbacks such as prolonged reaction times, low yields, excessive catalyst loading, and high temperatures. Although other silica-based catalysts like H2SO4-Silica, SBA-Pr-SO3H, and SSA can also catalyze the Biginelli reaction, they generally provide lower yields (Table 6, entries 2, 7, and 9). In particular, SSA (Table 6, entry 3) requires higher temperatures. Moreover, while some catalysts achieve yields comparable to SBA-16/SO3H, they often require greater catalyst amounts or higher acid densities. For example, H2SO4-Silica and SSA (Table 6, entries 2 and 9) necessitate nearly triple the acid density of SBA-16/SO3H, and sulfuric acid silica and SSA catalysts require almost ten times as much (Table 6, entries 1 and 3). Furthermore, catalysts like SBNPSA, MCM-41-R-SO3H, and MCM-41-APS-PMDA-NHSO3H (Table 6, entries 4, 5, and 11) require significantly larger catalyst quantities, even if their acid densities are lower. Another key advantage of SBA-16/SO3H is that most comparable catalysts either do not report recyclability (Table 6, entries 2, 3, 8, and 9) or involve complex syntheses with a variety of chemicals over prolonged periods. In contrast, SBA-16/SO3H can be prepared from SCBA (an industrial waste material) using a simpler experimental procedure, providing a more sustainable and efficient catalyst preparation route.
Reusability of catalyst
Under optimized conditions, the SCBA catalyst exhibited excellent reusability, maintaining a 98.69% yield even after five consecutive cycles (Fig. 13). This finding indicates that the catalyst is highly efficient and retains its catalytic capacity through multiple uses. In comparison, silica catalysts studied by Peyman82 and Srinivasa85 showed a decline in efficiency with repeated use. In contrast, the SCBA catalyst’s performance remained stable, demonstrating its superior durability and potential for sustainable catalytic applications.
Reusability of catalyst on Biginelli reaction. Reaction conditions: the reactions were carried out with methyl acetoacetate (7.5 mmol), benzaldehyde (5 mmol), urea (5 mmol) and SBA-16/SO3H (10 wt%) in ethanol at 105 °C for 7 h.
Green metric evaluation
Green assessment for the synthesis of SBA-16 and SBA-16-SO3H
A direct green assessment comparison was conducted between the preparation of SBA-16 and SBA-16/SO3H from SCBA in this study and the typical synthesis methods using TEOS87 as the starting material. This evaluation was performed using the DOZN™ 2.0 Green Chemistry Evaluator88,89,90. The software assessed the environmental impact of the syntheses, considering factors such as reaction time, synthesis steps, solvent usage, and waste generation. Chemical properties were obtained from the UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS) and Safety Data Sheets (SDS). DOZN™ 2.0, developed and tested by MilliporeSigma, is based on the 12 Principles of Green Chemistry, with its evaluation equations previously published80. However, DOZN™ 2.0 does not account for the life cycle impacts of raw materials; rather, it evaluates the risks associated with their use and their efficient consumption. Since SCBA does not have a product number in the Sigma-Aldrich database, we used fly ash (trace elements) (product number BCR176R) as a representative material. Additionally, the reported procedures for catalyst preparation from TEOS did not specify the amount of product obtained. Therefore, we assumed that the product yield was equivalent to that obtained from SCBA in this study, as the starting material quantities were similar. The values used in the DOZN™ 2.0 tool to calculate the green score are provided in Table S2 of the Supplementary Information.
In green chemistry assessments, comparing synthesis procedures helps identify more sustainable methods. Given that some catalyst synthesis procedures share similar steps, the descriptions below have been grouped to facilitate clear comparisons. These comparisons are based on individual scores for the 12 Green Chemistry Principles, three grouped category scores, and an overall (or aggregate) score (Table S3). A lower score indicates a greener synthesis. Figure 14 presents the aggregate scores for all materials analyzed. The overall score ranges from zero (representing the most or ideally green process) to 100 (indicating the least green process). These scores were calculated using all 12 Green Chemistry Principles (GCPs). Notably, the scores for SBA-16 and SBA-16/SO3H derived from SCBA are significantly lower than those from TEOS, highlighting a more optimized and environmentally friendly process.
Comparison of overall scores for SBA-16 and SBA-16/SO3H derived from SCBA or TEOS calculated using DOZN 2.0.
The preparation of SBA-16 and SBA-16/SO3H using SCBA, a renewable material, resulted in lower scores across several Green Chemistry Principles (GCPs) compared to synthesis from TEOS, as shown in Figs. 15 and 16. No significant differences were observed in GCP 3 (less hazardous chemical synthesis), GCP 4 (designing safer chemicals), GCP 5 (safer solvents and auxiliaries), GCP 8 (reducing derivatives), GCP 9 (catalysis), GCP 10 (design for degradation), GCP 11 (real-time analysis for pollution prevention), and GCP 12 (inherently safer chemistry for accident prevention) between the two methods for SBA-16 synthesis, as both follow similar procedures (Fig. 15). GCP 1 (waste prevention) emphasizes avoiding waste generation rather than treating it afterward84,85. In SBA-16 synthesis, water usage contributes significantly to waste. Since the SCBA-based process requires less water, it achieves a lower impact score for GCP 1. This also correlates with a slightly higher GCP 2 (atom economy) impact in the TEOS-based process. GCP 7 (use of renewable feedstocks) prioritizes renewable raw materials over depleting resources91. DOZN™ defines a renewable material as a "biobased product," meaning a product composed entirely or significantly of biological sources. The slight difference in GCP 7 scores reflects the renewable nature of SCBA. Although SBA-16 synthesis using TEOS occurs at a relatively low temperature (40–80 °C), the total reaction time (73 h) significantly increases its environmental impact under GCP 6 (design for energy efficiency). In contrast, the SCBA-based process operates at room temperature with a much shorter reaction time, reducing the impact score for GCP 6 by nearly 95%. For the synthesis of SBA-16/SO3H from both starting materials (SCBA and TEOS) (Fig. 16), the TEOS-based process exhibits significantly worse impacts (100%) across several Green Chemistry Principles (GCPs), including GCP 1–3, 5–7, and 12. These negative impacts result from the multistep synthesis, high reaction temperature, prolonged reaction time, excessive solvent use—including the toxic solvent toluene—and the slightly higher amount of explosive hydrogen peroxide. In contrast, the SCBA-based process offers a much greener alternative.
Comparison of SBA-16 preparation from SCBA or TEOS showing the 12 principle scores.
Comparison of SBA-16/SO3H preparation from SCBA or TEOS showing the 12 principle scores.
The 12 Green Chemistry Principles are categorized into three major groups (Fig. 17): Improved Resource Use (GCP 1, GCP 2, GCP 7, GCP 8, GCP 9, and GCP 11), Increased Energy Efficiency (GCP 6), and Reduced Human and Environmental Hazards (GCP 3, GCP 4, GCP 5, GCP 10, and GCP 12). The SCBA-based process demonstrates a greener impact in the Improved Resource Use category compared to the TEOS-based process, emphasizing the benefits of using renewable starting materials. Additionally, the SCBA-based process achieves a significantly lower impact score in Increased Energy Efficiency, highlighting its more sustainable synthesis design. In the Reduced Human and Environmental Hazards category, the SCBA-based process also shows lower impact scores than the TEOS-based process, with particularly notable improvements in the preparation of SBA-16/SO3H.
Group scores for SBA-16 and SBA-16/SO3H preparation from SCBA or TEOS showcasing the three major aspects of improved processes and products.
Green assessment for Biginelli reaction
Several green analytical chemistry metrics were used to assess the efficiency of the Biginelli reaction catalyzed by SBA-16/SO3H (Table 7; see Supporting Information for metric definitions and calculations)92,93,94. These metrics include the Process Mass Intensity (PMI) and the E-factor, which both measure different aspects of sustainability. PMI focuses on resource utilization and process optimization, while the E-factor emphasizes waste reduction. Ideally, a more environmentally sustainable process has a PMI close to 1 and an E-factor approaching 0, indicating minimal waste generation. Although the PMI and E-factor values for the processes examined are slightly higher than these ideal thresholds95, they remain low enough to suggest minimal waste production. Similar conclusions can be drawn from the solvent intensity (SI) and water intensity (WI) metrics, which also indicate relatively low resource consumption.
The sustainability of the process was further evaluated using the Green Motion tool93 (Fig. 18), which assigns penalty points (0–100) based on adherence to the 12 principles of green chemistry. Higher scores correspond to safer processes with lower environmental impact. The process involving our catalyst achieved a high score (75/100), reflecting its alignment with green chemistry principles, including high atom economy, low toxicity of reagents and solvents, operation at atmospheric pressure, no need for cooling despite heating, and excellent catalyst reusability. Detailed explanations of the Green Motion assessment are available in the Supporting Information. It is important to note that the lower scores (67/100) in the "Waste and Raw Materials" category stem from the use of synthetic raw materials—despite their potential derivation from natural sources—and the relatively high volume of solvent used. Nevertheless, the overall process achieved a score of 75/100, which the Green Motion standards classify as environmentally friendly. Recovering and reusing ethanol in future implementations could further improve this score.
Analysis of the sustainability profile of the methodology using the Green Motion metric tool.
Conclusions
The sulfonated SBA-16 catalyst synthesized from SCBA represents a significant advancement in sustainable catalyst development. By employing agro-industrial waste as the silica precursor, this approach addresses waste disposal issues while providing an environmentally friendly alternative to conventional materials. Notably, the SCBA-derived SBA-16 contains trace impurities that may enhance Lewis acidity, complementing the Brønsted acidity introduced by sulfonation. The combination of Brønsted and Lewis acidity, along with improved textural and functional properties, resulted in superior catalytic performance. The green synthesis of catalysts derived from SCBA was evaluated using DOZN™ software and compared to the conventional TEOS-based synthesis. The TEOS-based process exhibited several unfavorable impacts on the Green Chemistry Principles due to its less sustainable design. In contrast, the SCBA-based process demonstrated a greener approach, benefiting from the use of renewable starting materials and a simpler synthesis procedure. The SBA-16/SO3H catalyst achieved near-quantitative yields in the Biginelli reaction under mild conditions and demonstrated excellent recyclability and durability across multiple cycles. Its strong alignment with green chemistry principles is reflected in favorable metrics, including process mass intensity (PMI: 11.86–33.32 g/g), E-factor (10.86–32.32 g/g), solvent intensity (SI: 9.69–14.50 g/g), water intensity (WI: 3.28–9.36 g/g), and a high Green Motion assessment score (75/100). This work not only expands the potential applications of waste-derived catalysts in multicomponent reactions but also establishes a model for integrating sustainability into chemical process design, offering a scalable and cost-effective solution for industrial applications.
Data availability
All data generated or analysed during this study are included in this published article or its supplementary information files.
References
Sørensen, B. Hydrogen and fuel cells 2nd edn, 245–360 (Academic Press, 2012).
Gabrielli, P. et al. A comparison of environmental impact of various silicas using a green chemistry evaluator. One Earth 6, 682–704 (2023).
Hanif, I. Energy security and strategic importance of oil and gas in the energy sector. Energy Strategy Rev. 21, 16–24 (2018).
Capellán-Pérez, I., Mediavilla, M., de Castro, C., Carpintero, Ó. & Miguel, L. J. The impact of renewable energy on energy security and global development. Energy 77, 641–666 (2014).
Höök, M. & Tang, X. The future of global energy supply: The role of fossil fuels. Energy Policy 52, 797–809 (2013).
Rehman, A., Rauf, A., Ahmad, M., Chandio, A. A. & Deyuan, Z. Environmental impact assessment of energy production systems in Pakistan. Environ. Sci. Pollut. Res. 26, 21760–21773 (2019).
Alshehry, S. & Belloumi, M. Renewable energy and sustainable development in the middle east and North Africa. Renew. Sustain. Energy Rev. 41, 237–247 (2015).
Kabeyi, M. J. B. & Olanrewaju, O. A. Impact of renewable energy technologies in the african energy sector. J. Energy 2023, 5749122 (2023).
Solomon, S., Swapna, M., Xuan, V. T. & Mon, Y. Y. Optimization of sugarcane processing for biofuels production. Sugar Tech. 18, 559–575 (2016).
Garcia-Perez, T., Ortiz-Ulloa, J. A., Jara-Cobos, L. E. & Pelaez-Samaniego, M. R. Sustainable energy practices and challenges for the future. Sustainability 15, 15218 (2023).
Subhani, S., Subhani, S. M. & Bahurudeen, A. Utilization of sugarcane bagasse ash in binary, ternary, and quaternary blended cement concrete –A waste to Wealth approach. Mater. Today Sustain. 28, 100954 (2024).
Xu, Q., Ji, T., Gao, S. J., Yang, Z. & Wu, N. Characteristics and applications of sugar cane bagasse ash waste in cementitious materials. Materials 12, 39. https://doi.org/10.3390/ma12010039 (2018).
Abdalla, T., Hussein, A., Ahmed, Y. H. & Semmana, O. Strength, durability, and microstructure properties of concrete containing bagasse ash – A review of 15 years of perspectives, progress and future insights. Results Eng. 21, 24 (2024).
Pérez-Casas, J. A. et al. Sugarcane bagasse ash as an alternative source of silicon dioxide in sodium silicate synthesis. Materials 16, 6327 (2023).
Zarganes-Tzitzikas, T., Chandgude, A. L. & Dömling, A. Multicomponent reactions, union of MCRs and beyond. Chem. Rec. 15, 981–996 (2015).
Ahsan, W. in Dihydropyrimidinones as Potent Anticancer Agents (eds Mashooq Ahmad Bhat, Muneeb U. Rehman, & Amita Verma) 17–38 (Elsevier, 2023).
Ashok, M., Holla, B. S. & Kumari, N. S. Convenient one pot synthesis of some novel derivatives of thiazolo[2,3-b]dihydropyrimidinone possessing 4-methylthiophenyl moiety and evaluation of their antibacterial and antifungal activities. Eur. J. Med. Chem. 42, 380–385 (2007).
Hurst, E. W. & Hull, R. Two new synthetic substances active against viruses of the psittacosis-lymphogranuloma-trachoma group. J. Med. Pharmaceu Chem. 3, 215–229 (1961).
Bahekar, S. S. & Shinde, D. B. Synthesis and anti-inflammatory activity of some [4,6-(4-substituted aryl)-2-thioxo-1,2,3,4-tetrahydro-pyrimidin-5-yl]-acetic acid derivatives. Bioorg. Med. Chem. Lett. 14, 1733–1736 (2004).
Magerramov, A. M. et al. Synthesis and antioxidative properties of some 3,4-dihydropyrimidin-2(1H)ones (-thiones). Russ. J. Appl. Chem. 79, 787–790 (2006).
Kolosov, M. A., Orlov, V. D., Beloborodov, D. A. & Dotsenko, V. V. A chemical placebo: NaCl as an effective, cheapest, non-acidic and greener catalyst for Biginelli-type 3,4-dihydropyrimidin-2(1H)-ones (-thiones) synthesis. Mol. Diversity 13, 5–25 (2009).
Capellán-Pérez, I., Mediavilla, M., Castro, C., Carpintero, Ó. & Miguel, L. More growth? An unfeasible option to overcome critical energy constraints and climate change. Sustain. Sci. 10, 397–411 (2015).
Shaabani, A., Bazgir, A. & Teimouri, F. Ammonium Chloride catalyzed one-pot synthesis of 3,4-dihydropyrimidin-2-(1H)-ones under solvent-free conditions. Tetrahedron. Lett. 44, 857–859 (2003).
Hassani, Z., Islami, M. R. & Kalantari, M. An efficient one-pot synthesis of octahydroquinazolinone derivatives using catalytic amount of H2SO4 in water. Bioorg. Med. Chem. Lett. 16, 4479–4482 (2006).
Besoluk, S., Kucukislamoglu, M., Nebioglu, M., Zengin, M. & Arslan, M. Solvent-free synthesis of dihydropyrimidinones catalyzed by alumina sulfuric acid at room temperature. J. Iran. Chem. Soc. 5, 62–66 (2008).
Choudhary, V. R., Tillu, V. H., Narkhede, V. S., Borate, H. B. & Wakharkar, R. D. Microwave assisted solvent-free synthesis of dihydropyrimidinones by Biginelli reaction over Si-MCM-41 supported FeCl3 catalyst. Catal. Commun. 4, 449–453 (2003).
Wang, X. et al. PEG-SO3H as Catalyst for 3,4-dihydropyrimidones via biginelli reaction under microwave and solvent-free conditions. Synth. Commun. 36, 451–456 (2006).
Gopalakrishnan, M., Sureshkumar, P., Thanusu, J., Kanagarajan, V. & Ezhilarasi, M. R. ChemInform abstract: An expedient one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones catalyzed by ZIRCONIA nanopowder. An improved protocol for the Biginelli Cyclocondensation compounds in “Dry Media”. ChemInform 39, 142–147 (2008).
Maradur, S. P. & Gokavi, G. S. Heteropoly acid catalyzed synthesis of 3,4-dihydropyrimidin-2(1H)-ones. Catal. Commun. 8, 279–284 (2007).
Martı́nez, S. et al. Silica aerogel-iron oxide nanocomposites: Recoverable catalysts in conjugate additions and in the Biginelli reaction. Tetrahedron 59, 1553–1556 (2003).
Ahmad, S., Afshin, S., Abbas, R. & Ali Hossein, R. Ionic liquid/silica sulfuric acid promoted fast synthesis of a Biginelli-like scaffold reaction. Lett. Organ. Chem. 4, 68–71 (2007).
Gupta, R., Paul, S. & Gupta, R. Covalently anchored sulfonic acid onto silica as an efficient and recoverable interphase catalyst for the synthesis of 3,4-dihydropyrimidinones/thiones. J. Mol. Catal. A: Chem. 266, 50–54 (2007).
Salehi, P., Dabiri, M., Zolfigol, M. A. & Bodaghi Fard, M. A. Silica sulfuric acid: an efficient and reusable catalyst for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones. Tetrahedron Lett. 44, 2889–2891 (2003).
Chen, W. Y., Qin, S. D. & Jin, J. R. Efficient Biginelli reaction catalyzed by sulfamic acid or silica sulfuric acid under solvent-free conditions. Synth. Commun. 37, 47–52 (2007).
Palos-Barba, V. et al. SBA-16 cage-like porous material modified with APTES as an adsorbent for Pb2+ ions removal from aqueous solution. Materials 13, 927 (2020).
Cepanec, I., Litvić, M., Bartolinčić, A. & Lovrić, M. Ferric chloride/tetraethyl orthosilicate as an efficient system for synthesis of dihydropyrimidinones by Biginelli reaction. Tetrahedron 61, 4275–4280 (2005).
Bhanudas, N. & Narendra Nath, G. A review on chemical methodologies for preparation of mesoporous silica and alumina based materials. Recent Patents Nanotechnol. 3, 213–224 (2009).
Shirini, F., Marjani, K., Nahzomi, H. T. & Zolfigol, M. A. Silica triflate as an efficient reagent for the solvent-free synthesis of coumarins. Chin. Chem. Lett. 18, 909–911 (2007).
Shabana, K. K., Narendranath, S. B., Nimisha, N. P. & Sakthivel, A. Synergistically stabilized SAPO-37-tetragonal zirconia composites: A promising catalyst for ethyl levulinate synthesis. Chem. Commun. 61, 1136–1139 (2025).
Sharma, P., Prakash, J. & Kaushal, R. An insight into the green synthesis of SiO2 nanostructures as a novel adsorbent for removal of toxic water pollutants. Environ. Res. 212, 113328 (2022).
Zhao, D. et al. Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 angstrom pores. Science 279, 548–552 (1998).
Yadav, R. et al. Recent advances in the preparation and applications of organo-functionalized porous materials. Chem.– An Asian J. 15, 2588–2621 (2020).
Karade, H. N., Sathe, M. & Kaushik, M. P. Synthesis of 4-aryl substituted 3,4-dihydropyrimidinones using silica-chloride under solvent free conditions. Molecules 12, 1341–1351 (2007).
Tsoncheva, T. et al. Preparation, characterization and catalytic behavior in methanol decomposition of nanosized iron oxide particles within large pore ordered mesoporous silicas. Microporous Mesoporous Mater. 89, 209–218 (2006).
Hwang, Y. K., Chang, J.-S., Kwon, Y.-U. & Park, S.-E. Microwave synthesis of cubic mesoporous silica SBA-16. Microporous Mesoporous Mater. 68, 21–27 (2004).
Zhu, Y., Dong, Y., Zhao, L. & Yuan, F. Preparation and characterization of Mesopoous VOx/SBA-16 and their application for the direct catalytic hydroxylation of benzene to phenol. J. Mol. Catal. A: Chem. 315, 205–212 (2010).
Wei, J. et al. Thermal and hydrothermal stability of amino-functionalized SBA-16 and promotion of hydrophobicity by silylation. Microporous Mesoporous Mater. 117, 596–602 (2009).
Xue, X. & Li, F. Removal of Cu(II) from aqueous solution by adsorption onto functionalized SBA-16 mesoporous silica. Microporous Mesoporous Mater. 116, 116–122 (2008).
Tu, J. et al. Humidity sensitive property of Li-doped 3D periodic mesoporous silica SBA-16. Sens. Actuators, B Chem. 136, 392–398 (2009).
Zhao, D., Huo, Q., Feng, J., Chmelka, B. F. & Stucky, G. D. Nonionic triblock and star diblock copolymer and oligomeric surfactant syntheses of highly ordered, hydrothermally stable, mesoporous silica structures. J. Am. Chem. Soc. 120, 6024–6036 (1998).
Boza, A. F. et al. Synthesis of α-aminophosphonates using a mesoporous silica catalyst produced from sugarcane bagasse ash. RSC Adv. 6, 23981–23986 (2016).
Maheswari, R. et al. Preparation and characterization of mesostructured Zr-SBA-16: Efficient Lewis acidic catalyst for Hantzsch reaction. J. Porous Mater. 22, 705–711 (2015).
"Safety Data Sheet: Tetraethyl orthosilicate", can be found under https://www.chemos.de/import/data/msds/GB_en/78-10-4-A0070897-GB-en.pdf (accessed 25 December 2024)
Gupta, R. & Pathak, D. D. Synthesis of 2-iminothiazolidin-4-ones using guanine functionalized SBA-16 as a solid base catalyst. Tetrahedron Lett. 85, 153497 (2021).
Chindaprasirt, P. & Rattanasak, U. Eco-production of silica from sugarcane bagasse ash for use as a photochromic pigment filler. Sci. Rep. 10, 9890 (2020).
Karnopp, J. et al. Preparation of the rutin-SBA-16 drug delivery system. J. Biomater. Nanobiotechnol. 11, 1–13 (2020).
Sarkar, M., Ali, M., Rahman, M. L. & Yusoff, M. Preparation of mesoporous SBA-16 silica-supported biscinchona alkaloid ligand for the asymmetric dihydroxylation of olefins. J. Nanomater. 2014, 1–5 (2014).
Vanichvattanadecha, C., Singhapong, W. & Jaroenworaluck, A. Different sources of silicon precursors influencing on surface characteristics and pore morphologies of mesoporous silica nanoparticles. Appl. Surf. Sci. 513, 145568 (2020).
Yu, B. et al. pH-responsive gelatin polymer-coated silica-based mesoporous composites for the sustained-release of indomethacin. Heliyon 9, e13705 (2023).
Arun, R., Athira, M. P., Remello, S. N. & Haridas, S. SBA-15-SO3H catalysed room temperature synthesis of 2-aryl benzimidazoles and benzothiazoles. React. Kinet. Mech. Catal. 136, 2277–2294 (2023).
Zulkifli, N. S. C., Ab Rahman, I., Mohamad, D. & Husein, A. A green sol–gel route for the synthesis of structurally controlled silica particles from rice husk for dental composite filler. Ceram. Int. 39, 4559–4567 (2013).
Sun, H. et al. Mesostructured SBA-16 with excellent hydrothermal, thermal and mechanical stabilities: Modified synthesis and its catalytic application. J. Colloid Interface Sci. 333, 317–323 (2009).
Akopyan, A. V., Shlenova, A. O., Polikarpova, P. D. & Vutolkina, A. V. High-performance heterogeneous oxidative desulfurization catalyst with Brønsted acid sites. Pet. Chem. 62, 636–642 (2022).
Dadkar, N., Tomar, B. & Satapathy, B. Evaluation of flyash-filled and aramid fibre reinforced hybrid polymer matrix composites (PMC) for friction braking applications. Mater. Design 30, 4369–4376 (2009).
Teso, W. A. & Bayisa, Y. M. Solid sulfonated silica acid catalyst for epoxidation of podocarpus falcatus seed oil. Biomass Conversion Biorefinery (2021).
Ahmad, S., Wong, Y. C. & Veloo, K. V. Sugarcane bagasse powder as biosorbent for reactive red 120 removals from aqueous solution. IOP Conf. Series: Earth Environ. Sci. 140, 012027 (2018).
Sharma, P., Ponnusamy, E., Ghorai, S. & Colacot, T. J. DOZNTM 2.0: A quantitative green chemistry evaluator for a sustainable future. J. Organomet. Chem. 970–971, 122367 (2022).
Suyanta, S. & Mudasir, M. Optimizing rice husk silica mass and sonication time for a more efficient and environmentally friendly synthesis of SBA-15. Indonesian J. Chem. (2022).
Berenguer, R. A., Capraro, A. P. B., de Medeiros, M. H. F., Carneiro, A. M. P. & De Oliveira, R. A. Sugar cane bagasse ash as a partial substitute of Portland cement: Effect on mechanical properties and emission of carbon dioxide. J. Environ. Chem. Eng. 8, 103655 (2020).
Shirini, F., Mamaghani, M. & Seddighi, M. Sulfonated rice husk ash (RHA-SO3H): A highly powerful and efficient solid acid catalyst for the chemoselective preparation and deprotection of 1,1-diacetates. Catal. Commun. 36, 31–37 (2013).
Andrade, G. F., Gomide, V. S., da Silva, A. C., Goes, A. M. & de Sousa, E. M. B. An in situ synthesis of mesoporous SBA-16/hydroxyapatite for ciprofloxacin release: In vitro stability and cytocompatibility studies. J. Mater. Sci.: Mater. Med. 25, 2527–2540 (2014).
Azizi, S. N., Ghasemi, S. & Yazdani-Sheldarrei, H. Synthesis of mesoporous silica (SBA-16) nanoparticles using silica extracted from stem cane ash and its application in electrocatalytic oxidation of methanol. Int. J. Hydrogen Energy 38, 12774–12785 (2013).
Ho, S.-T., Dinh, Q.-K., Tran, T.-H., Nguyen, H.-P. & Nguyen, T.-D. One-step synthesis of ordered Sn-substituted SBA-16 mesoporous materials using prepared silica source of rice husk and their selectively catalytic activity. Canadian J. Chem. Eng. 91, 34–46 (2013).
Stevens, W. J. J. et al. Investigation of the morphology of the mesoporous SBA-16 and SBA-15 materials. J. Phys. Chem. B 110, 9183–9187 (2006).
Khatri, P. K., Manchanda, M., Ghosh, I. K. & Jain, S. L. Polymer impregnated sulfonated carbon composite solid acid catalyst for alkylation of phenol with methyl-tert-butyl ether. RSC Adv. 5, 3286–3290 (2015).
Barry, F. The influence of temperature on chemical reaction in general. Am. J. Bot. 1, 203–225 (1914).
Nemati, F. & Alizadeh, S. G. Bi-SO3H functionalized ionic liquid based on DABCO: New and efficient catalyst for facile synthesis of dihydropyrimidinones. J. Chem. 2013, 235818 (2013).
Alehi, P., Dabiri, M., Zolfigol, M. A. & Bodaghi Fard, M. A. Silica sulfuric acid: an efficient and reusable catalyst for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones. Tetrahedron Lett. 44, 2889–2891 (2003).
Pourmousavi, S. A. & Hasani, M. H2SO4-silica catalyzed one-pot and efficient synthesis of dihydropyrimidinones under solvent-free conditions. J. Chem. 2011, 158612 (2011).
Jetti, S. R., Bhatewara, A., Kadre, T. & Jain, S. Silica-bonded N-propyl sulfamic acid as an efficient recyclable catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones under heterogeneous conditions. Chin. Chem. Lett. 25, 469–473 (2014).
Mahdavinia, G. H. & Sepehrian, H. MCM-41 anchored sulfonic acid (MCM-41-R-SO3H): A mild, reusable and highly efficient heterogeneous catalyst for the Biginelli reaction. Chin. Chem. Lett. 19, 1435–1439 (2008).
Gholamzadeh, P., Mohammadi Ziarani, G., Lashgari, N., Badiei, A. & Asadiatouei, P. Silica functionalized propyl sulfonic acid (SiO2-Pr-SO3H): An efficient catalyst in organic reactions. J. Mol. Catal. A Chem. 391, 208–222 (2014).
Ziarani, G., Azizi, M., Hajiabbasi, P. & Badiei, A. Application of sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) for the preparation of 4,6-diarylpyrimidin-2(1H)-ones. Quím. Nova 38, 466–470 (2015).
Bouguessa, I., Dehamchia, M., Bayou, S., Gouasmia, A. & Régaïnia, Z. Silica sulfuric acid catalyzed synthesis of pyrimidines and new fused pyrimido-purines via Biginelli reaction. J. Chem. Technol. 29, 504–511 (2021).
Frolov, N. A. & Vereshchagin, A. N. Piperidine derivatives: Recent advances in synthesis and pharmacological applications. Int. J. Mol. Sci. 24, 2937 (2023).
Valiey, E., Dekamin, M. G. & Alirezvani, Z. Sulfamic acid pyromellitic diamide-functionalized MCM-41 as a multifunctional hybrid catalyst for melting-assisted solvent-free synthesis of bioactive 3,4-dihydropyrimidin-2-(1H)-ones. Sci. Rep. 11, 11199 (2021).
Peng, Z.-W., Hsieh, P.-T., Yuan Jun, L., Huang, C.-J. & Li, C.-C. Investigation on blistering behavior for n-type silicon solar cells. Energy Procedia 77, 827–831 (2015).
DeVierno Kreuder, A. et al. A method for assessing greener alternatives between chemical products following the 12 principles of green chemistry. ACS Sustain. Chem. Eng. 5, 2927–2935 (2017).
Brambila, C. et al. A comparison of environmental impact of various silicas using a green chemistry evaluator. ACS Sustain. Chem. Eng. 10, 5288–5298 (2022).
Anastas, P. & Eghbali, N. Green chemistry: Principles and practice. Chem. Soc. Rev. 39, 301–312 (2010).
Valiey, E. & Dekamin, M. G. Design and characterization of an urea-bridged PMO supporting Cu(II) nanoparticles as highly efficient heterogeneous catalyst for synthesis of tetrazole derivatives. Sci. Rep. 12, 18139 (2022).
Augé, J. A new rationale of reaction metrics for green chemistry. Mathematical expression of the environmental impact factor of chemical processes. Green Chem. 10, 225–231 (2008).
Phan, T. V. T., Gallardo, C. & Mane, J. GREEN MOTION: A new and easy to use green chemistry metric from laboratories to industry. Green Chem. 17, 2846–2852 (2015).
Andraos, J. Unification of reaction metrics for green chemistry: Applications to reaction analysis. Org. Process Res. Dev. 9, 519–519 (2005).
Ma, X. et al. Synthesis of tetrahydropyrrolothiazoles through one-pot and four-component N, S-acetalation and decarboxylative [3+2] cycloaddition. Green Synthesis Catal. 2, 74–77 (2021).
Acknowledgements
This research project was financially supported by Mahasarakham University and the Centre of Excellence for Innovation in Chemistry (PERCH-CIC), Office of the Higher Education Commission, Ministry of Education, Thailand. Andrew J. Hunt would like acknowledge funding by National Research Council of Thailand (NRCT) (Grant number: N42A650240).
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K.S. and P.N. wrote the main manuscript text. All authors participated in data analysis. P.N. conceived the study, designed the study, coordinated the study, carried out data analysis, and interpreted the results. All authors reviewed the manuscript.
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Saenthornsin, K., Hunt, A.J., Limtragool, Oa. et al. Mesoporous SBA-16/SO3H from waste sugarcane bagasse ash for efficient Biginelli reactions. Sci Rep 15, 15738 (2025). https://doi.org/10.1038/s41598-025-99670-w
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DOI: https://doi.org/10.1038/s41598-025-99670-w
