Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

Rethinking carbanion chemistry from donor substituents to weakly coordinating carbanions

Nature Reviews Chemistry volume 9, pages 523–536 (2025)Cite this article

Subjects

Abstract

Carbanionic compounds provide unique reactivity patterns resulting from the high negative partial charge at the carbon centre, making them invaluable in chemical synthesis. They are important reagents in synthesis, including for challenging metalation reactions or the formation of C–C bonds. Despite this, broader applications have long been limited by their high reactivity and sensitivity to air and moisture. However, recent studies have underscored the versatility of carbanions beyond their traditional role as strong bases and nucleophiles. Utilization of molecular design strategies has opened applications such as their use as electron-donating groups isoelectronic with amines, ambiphilic reagents and even as weakly coordinating anions. In this review article, we provide an overview of these emerging uses of carbanionic compounds, aiming to inspire a broader rethinking of their potential and to encourage the development of new applications.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on SpringerLink
  • Instant access to the full article PDF.

USD 39.95

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Insertion reactions of carbenoids.
Fig. 2: Ligand exchange reactions at ylidic and carbanionic carbon centres, involving the replacement of phosphino and diazo groups by small molecules.
Fig. 3: Carbanionic functional groups used in the design of phosphine ligands.
Fig. 4: Ylidic substituents used for the stabilization of electron-deficient group 13 and group 14 compounds.
Fig. 5: Weakly coordinating anions.
Fig. 6: Brønsted super acids and their application in catalysis.

Similar content being viewed by others

References

  1. Seyferth, D. Zinc alkyls, Edward Frankland, and the beginnings of main-group organometallic chemistry. Organometallics 20, 2940–2955 (2001).

    Article  CAS  Google Scholar 

  2. Grignard, V. Sur quelques nouvelles combinaisons organométalliques du magnésium et leur application à des synthèses d’alcools et d’hydrocarbures. Compt. Rend. Hebd. Seances Acad. Sci. 130, 1322–1324 (1900).

    CAS  Google Scholar 

  3. Schlenk, W. & Holtz, J. Über die einfachsten metallorganischen Alkaliverbindungen. Ber. Dtsch. Chem. Ges. 50, 262–274 (1917).

    Article  CAS  Google Scholar 

  4. Carey, F. A. & Sundberg, R. J. in Advanced Organic Chemistry 373–402 (Springer, 1984).

  5. Snieckus, V. Directed ortho metalation. Tertiary amide and O-carbamate directors in synthetic strategies for polysubstituted aromatics. Chem. Rev. 90, 879–933 (1990).

    Article  CAS  Google Scholar 

  6. Armstrong, D. R. et al. Directed meta-metalation using alkali-metal-mediated zincation. Angew. Chem. Int. Ed. 45, 3775–3778 (2006).

    Article  CAS  Google Scholar 

  7. Martínez-Martínez, A. J., Kennedy, A. R., Mulvey, R. E. & O’Hara, C. T. Directed ortho-meta’- and meta-meta’-dimetalations: a template base approach to deprotonation. Science 346, 834–837 (2014).

    Article  PubMed  Google Scholar 

  8. Bole, L. J. & Hevia, E. Activation of polar organometallic reagents with alkali-metal alkoxides. Nat. Synth. 1, 195–202 (2022).

    Article  Google Scholar 

  9. Gentner, T. X. & Mulvey, R. E. Alkali-metal mediation: diversity of applications in main-group organometallic chemistry. Angew. Chem. Int. Ed. 60, 9247–9262 (2020).

    Article  Google Scholar 

  10. Harder, S. From limestone to catalysis: application of calcium compounds as homogeneous catalysts. Chem. Rev. 110, 3852–3876 (2010).

    Article  CAS  PubMed  Google Scholar 

  11. Magre, M., Szewczyk, M. & Rueping, M. s-Block metal catalysts for the hydroboration of unsaturated bonds. Chem. Rev. 122, 8261–8312 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Gil-Negrete, J. M. & Hevia, E. Main group bimetallic partnerships for cooperative catalysis. Chem. Sci. 12, 1982–1992 (2021).

    Article  CAS  Google Scholar 

  13. Fazekas, E. et al. Main group metal polymerisation catalysts. Chem. Soc. Rev. 51, 8793–8814 (2022).

    Article  CAS  PubMed  Google Scholar 

  14. Fiorentini, F. et al. Understanding catalytic synergy in dinuclear polymerization catalysts for sustainable polymers. Nat. Commun. 14, 4783 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Colella, M., Nagaki, A. & Luisi, R. Flow technology for the genesis and use of (highly) reactive organometallic reagents. Chem. Eur. J. 26, 19–32 (2020).

    Article  CAS  PubMed  Google Scholar 

  16. Slavík, P., Trowse, B. R., O’Brien, P. & Smith, D. K. Organogel delivery vehicles for the stabilization of organolithium reagents. Nat. Chem. 15, 319–325 (2023).

    Article  PubMed  PubMed Central  Google Scholar 

  17. Mulks, F. F. et al. Continuous, stable, and safe organometallic reactions in flow at room temperature assisted by deep eutectic solvents. Chem 8, 3382–3394 (2022).

    Article  CAS  Google Scholar 

  18. Vidal, C., García-Álvarez, J., Hernán-Gómez, A., Kennedy, A. R. & Hevia, E. Introducing deep eutectic solvents to polar organometallic chemistry: chemoselective addition of organolithium and Grignard reagents to ketones in air. Angew. Chem. Int. Ed. 53, 5969–5973 (2014).

    Article  CAS  Google Scholar 

  19. Rodríguez-Álvarez, M. J. et al. Recent advancements in the utilization of s-block organometallic reagents in organic synthesis with sustainable solvents. Molecules 29, 1422 (2024).

    Article  PubMed  PubMed Central  Google Scholar 

  20. Olmstead, M. M. & Power, P. P. The isolation and X-ray structures of lithium crown ether salts of the free phenyl carbanions [CHPh2]− and [CPh3]−. J. Am. Chem. Soc. 107, 2174–2175 (1985).

    Article  CAS  Google Scholar 

  21. Alexander, J. S. & Ruhlandt-Senge, K. Barium triphenylmethanide: an examination of anion basicity. Angew. Chem. Int. Ed. 40, 2658–2660 (2001).

    Article  CAS  Google Scholar 

  22. Yanai, H. et al. Synthesis, characterization, and applications of zwitterions containing a carbanion moiety. Angew. Chem. Int. Ed. 52, 1560–1563 (2013).

    Article  CAS  Google Scholar 

  23. Luisi, R. & Capriati, V. Lithium Compounds in Organic Synthesis (Wiley, 2014).

  24. Closs, G. L. & Moss, R. A. Carbenoid formation of arylcyclopropanes from olefins, benzal bromides, and organolithium compounds and from photolysis of aryldiazomethanes. J. Am. Chem. Soc. 86, 4042–4053 (1964).

    Article  CAS  Google Scholar 

  25. Colella, M. et al. Straightforward chemo- and stereoselective fluorocyclopropanation of allylic alcohols: exploiting the electrophilic nature of the not so elusive fluoroiodomethyllithium. Chem. Commun. 55, 8430–8433 (2019).

    Article  CAS  Google Scholar 

  26. Kelly, C. B. Modern cyclopropanation via non-traditional building blocks. ChemCatChem 16, e202400110 (2024).

    Article  CAS  Google Scholar 

  27. Matteson, D. S. & Majumdar, D. α-Chloro boronic esters from homologation of boronic esters. J. Am. Chem. Soc. 102, 7588–7590 (1980).

    Article  CAS  Google Scholar 

  28. Liu, Q. & Dong, Q. Carbenoids with sulfinate as nucleofuge for Matteson-type homologation: direct insertion of oxygen- and nitrogen-substituted units into carbon-boron bond. Angew. Chem. Int. Ed. 63, e202411980 (2024).

    Article  CAS  Google Scholar 

  29. Cason, G. et al. α-Sulfinyl benzoates as precursors to Li and Mg carbenoids for the stereoselective iterative homologation of boronic esters. J. Am. Chem. Soc. 139, 11877–11886 (2017).

    Article  Google Scholar 

  30. Burns, M. et al. Assembly-line synthesis of organic molecules with tailored shapes. Nature 513, 183–188 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Wu, J. et al. Synergy of synthesis, computation and NMR reveals correct baulamycin structures. Nature 547, 436–440 (2017).

    Article  CAS  PubMed  Google Scholar 

  32. Aiken, S. G. et al. Iterative synthesis of 1,3-polyboronic esters with high stereocontrol and application to the synthesis of bahamaolide A. Nat. Chem. 15, 248–256 (2023).

    Article  CAS  PubMed  Google Scholar 

  33. Fasano, V. et al. Automated stereocontrolled assembly-line synthesis of organic molecules. Nat. Synth. 1, 902–907 (2022).

    Article  CAS  Google Scholar 

  34. Blair, D. J. et al. Automated iterative Csp3–C bond formation. Nature 604, 92–97 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Ielo, L., Pillari, V., Miele, M., Castiglione, D. & Pace, V. Carbenoid-mediated homologation tactics for assembling (fluorinated) epoxides and aziridines. Synlett 32, 551–560 (2021).

    Article  CAS  Google Scholar 

  36. Bennett, S. H. et al. Difunctionalization of C–C σ-bonds enabled by the reaction of bicyclo[1.1.0]butyl boronate complexes with electrophiles: reaction, development, scope, and stereochemical origins. J. Am. Chem. Soc. 142, 16766–16775 (2020).

    Article  CAS  PubMed  Google Scholar 

  37. Fordham, J. M., Grayson, M. N. & Aggarwal, V. K. Vinylidene homologation of boronic esters and its application to the synthesis of the proposed structure of machillene. Angew. Chem. Int. Ed. 58, 15268–15272 (2019).

    Article  CAS  Google Scholar 

  38. Chen, M., Tugwell, T. H., Liu, P. & Dong, G. Synthesis of alkenyl boronates through stereoselective vinylene homologation of organoboronates. Nat. Synth. 3, 337–346 (2024).

    Article  CAS  Google Scholar 

  39. Xie, Q. & Dong, G. Aza-Matteson reactions via controlled mono- and double-methylene insertions into nitrogen–boron bonds. J. Am. Chem. Soc. 143, 14422–14427 (2021).

    Article  CAS  PubMed  Google Scholar 

  40. Xie, Q., Zhang, R. & Dong, G. Programmable amine synthesis via iterative boron homologation. Angew. Chem. Int. Ed. 62, e202307118 (2023).

    Article  CAS  Google Scholar 

  41. Xie, Q. & Dong, G. Programmable ether synthesis enabled by Oxa-Matteson reaction. J. Am. Chem. Soc. 144, 8498–8503 (2022).

    Article  CAS  PubMed  Google Scholar 

  42. Pace, V. et al. Bromomethyllithium-mediated chemoselective homologation of disulfides to dithioacetals. Chem. Commun. 52, 2639–2642 (2016).

    Article  CAS  Google Scholar 

  43. Roque, J. B., Kuroda, Y., Göttemann, L. T. & Sarpong, R. Deconstructive diversification of cyclic amines. Nature 564, 244–248 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Jurczyk, J. et al. Photomediated ring contraction of saturated heterocycles. Science 373, 1004–1012 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. Kennedy, S. H., Dherange, B. D., Berger, K. J. & Levin, M. D. Skeletal editing through direct nitrogen deletion of secondary amines. Nature 593, 223–227 (2021).

    Article  CAS  PubMed  Google Scholar 

  46. Reisenbauer, J. C., Green, O., Franchino, A., Finkelstein, P. & Morandi, B. Late-stage diversification of indole skeletons through nitrogen atom insertion. Science 377, 1104–1109 (2022).

    Article  CAS  PubMed  Google Scholar 

  47. Ciamician, G. L. & Dennstedt, M. Ueber die Einwirkung des Chloroforms auf die Kaliumverbindung Pyrrols. Ber. Dtsch. Chem. Ges. 14, 1153–1163 (1881).

    Article  Google Scholar 

  48. Guo, H., Qiu, S. & Xu, P. One-carbon ring expansion of indoles and pyrroles: a straightforward access to 3-fluorinated quinolines and pyridines. Angew. Chem. Int. Ed. 64, e202317104 (2023).

    Google Scholar 

  49. Tonner, R. & Frenking, G. C(NHC)2: divalent carbon(0) compounds with N-heterocyclic carbene ligands—theoretical evidence for a class of molecules with promising chemical properties. Angew. Chem. Int. Ed. 46, 8695–8698 (2007).

    Article  CAS  Google Scholar 

  50. Himmel, D., Krossing, I. & Schnepf, A. Dative bonds in main-group compounds: a case of fewer arrows! Angew. Chem. Int. Ed. 53, 370–374 (2014).

    Article  CAS  Google Scholar 

  51. Frenking, G. Dative bonds in main-group compounds: a case of more arrows! Angew. Chem. Int. Ed. 53, 6040–6046 (2014).

    Article  CAS  Google Scholar 

  52. Antoni, P. W., Reitz, J. & Hansmann, M. M. N2/CO exchange at a vinylidene carbon center: stable alkylidene ketenes and alkylidene thioketenes from 1,2,3-triazole derived diazoalkenes. J. Am. Chem. Soc. 143, 12878–12885 (2021).

    Article  CAS  PubMed  Google Scholar 

  53. Feuerstein, W., Varava, P., Fadaei-Tirani, F., Scopelliti, R. & Severin, K. Synthesis, structural characterization, and coordination chemistry of imidazole-based alkylidene ketenes. Chem. Commun. 57, 11509–11512 (2021).

    Article  CAS  Google Scholar 

  54. Antoni, P. W., Golz, C., Holstein, J. J., Pantazis, D. A. & Hansmann, M. M. Isolation and reactivity of an elusive diazoalkene. Nat. Chem. 13, 587–593 (2021).

    Article  CAS  PubMed  Google Scholar 

  55. Jörges, M., Krischer, F. & Gessner, V. H. Transition metal–free ketene formation from carbon monoxide through isolable ketenyl anions. Science 378, 1331–1336 (2022).

    Article  PubMed  Google Scholar 

  56. Xu, M., Jupp, A. R. & Stephan, D. W. Acyl-phosphide anions via an intermediate with carbene character: reactions of K[PtBu2] and CO. Angew. Chem. Int. Ed. 58, 3548–3552 (2019).

    Article  CAS  Google Scholar 

  57. Xu, M., Qu, Z.-W., Grimme, S. & Stephan, D. W. Lithium dicycloxylamide in transition-metal-free Fischer–Tropsch chemistry. J. Am. Chem. Soc. 143, 634–638 (2021).

    Article  CAS  PubMed  Google Scholar 

  58. Wang, T. et al. Steric influence on reactions of benzyl potassium species with CO. Chem. Asian J. 16, 3640–3644 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Jörges, M. et al. Phosphinoyl-substituted ketenyl anions: synthesis and substituent effects on the structural properties. Organometallics 43, 585–593 (2024).

    Article  PubMed  PubMed Central  Google Scholar 

  60. Krischer, F., Jörges, M., Leung, T.-F., Darmandeh, H. & Gessner, V. H. Selectivity control of the ligand exchange at carbon in α-metallated ylides as a route to ketenyl anions. Angew. Chem. Int. Ed. 62, e202309629 (2023).

    Article  CAS  Google Scholar 

  61. Krischer, F., Swamy, V. S. V. S. N., Feichtner, K.-S., Ward, R. J. & Gessner, V. H. The cyanoketenyl anion [NC3O]−. Angew. Chem. Int. Ed. 63, e202403766 (2024).

    Article  CAS  Google Scholar 

  62. Wang, T. et al. Synthesis and reactivity of the [NCCCO]− cyanoketenate anion. Angew. Chem. Int. Ed. 63, e202402728 (2024).

    Article  CAS  Google Scholar 

  63. Le Dé, Q. et al. Isolation and structure elucidation of the heterocumulene anions [NCC‒L]− (L=CO, CS, N2). Angew. Chem. Int. Ed. 64, e202422496 (2025).

    Article  Google Scholar 

  64. Wei, R., Wang, X.-F., Ruiz, D. A. & Liu, L. L. Stable ketenyl anions via ligand exchange at an anionic carbon as powerful synthons. Angew. Chem. Int. Ed. 62, e202219211 (2023).

    Article  CAS  Google Scholar 

  65. Duari, P., Mondal, S., Jörges, M. & Gessner, V. H. The lithium effect in ketenyl anion chemistry. Chem. Commun. 60, 9372–9375 (2024).

    Article  CAS  Google Scholar 

  66. Xu, M., Wang, T., Qu, Z.-W., Grimme, S. & Stephan, D. W. Reactions of a dilithiomethane with CO and N2O: an avenue to an anionic ketene and a hexafunctionalized benzene. Angew. Chem. Int. Ed. 60, 25281–25285 (2021).

    Article  Google Scholar 

  67. Koike, T., Yu, J.-K. & Hansmann, M. M. Ph3PCN2: a stable reagent for carbon-atom transfer. Science 385, 305–311 (2024).

    Article  CAS  PubMed  Google Scholar 

  68. Genoux, A. & Severin, K. Nitrous oxide as diazo transfer reagent. Chem. Sci. 15, 13605–13617 (2024).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  69. Sun, Q. et al. Spiro-C(sp3)-atom transfer: creating rigid three-dimensional structures with Ph2SCN2. Science 387, 885–892 (2025).

    Article  CAS  PubMed  Google Scholar 

  70. He, Y., Lyu, Y., Tymann, D., Antoni, P. W. & Hansmann, M. M. Cleavage of carbodicarbenes with N2O for accessing stable diazoalkenes: two-fold ligand exchange at a C(0)-atom. Angew. Chem. Int. Ed. 64, e202415228 (2024).

    Article  Google Scholar 

  71. Ward, R. J. et al. An azide-free synthesis of metallodiazomethanes using nitrous oxide. J. Am. Chem. Soc. 146, 24602–24608 (2024).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  72. Gilbert, J. C. & Weerasooriya, U. Diazoethenes: their attempted synthesis from aldehydes and aromatic ketones by way of the Horner-Emmons modification of the Wittig reaction. A facile synthesis of alkynes. J. Org. Chem. 47, 1837–1845 (1982).

    Article  CAS  Google Scholar 

  73. Wang, X.-F., Wei, R., Liang, Q. & Liu, L. L. Stable crystalline keteniminyl anions. Chem 11, 102444 (2025).

    Article  CAS  Google Scholar 

  74. Mondal, S. et al. PPh3/isocyanide and N2/isocyanide exchange: pathways to isolable alkali metal keteniminyl anions. Angew. Chem. Int. Ed. https://doi.org/10.1002/anie.202504325 (2025).

  75. Race, J. J. & Albrecht, M. Pyridylidene amines and amides: donor-flexible ligands for catalysis. ACS Catal. 13, 9891–9904 (2023).

    Article  CAS  Google Scholar 

  76. Ruiz-Castillo, P. & Buchwald, S. L. Applications of palladium-catalyzed C‒N cross-coupling reactions. Chem. Rev. 116, 12564–12649 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  77. Biffis, A., Centomo, P., Del Zotto, A. & Zecca, M. Pd metal catalysts for cross-couplings and related reactions in the 21st century: a critical review. Chem. Rev. 118, 2249–2295 (2018).

    Article  CAS  PubMed  Google Scholar 

  78. Collado, A., Nelson, D. J. & Nolan, S. P. Optimizing catalyst reaction conditions gold(I) catalysis−ligand development. Chem. Rev. 121, 8559–8612 (2021).

    Article  CAS  PubMed  Google Scholar 

  79. Zheng, Z. et al. Homogeneous gold-catalyzed oxidation reactions. Chem. Rev. 121, 8979–9038 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  80. Chen, L., Ren, P. & Carrow, B. P. Tri(1-adamantyl)phosphine: expanding the boundary of electron-releasing character available to organophosphorus compounds. J. Am. Chem. Soc. 138, 6392–6395 (2016).

    Article  CAS  PubMed  Google Scholar 

  81. Fleckenstein, C. A. & Plenio, H. Sterically demanding trialkylphosphines for palladium-catalyzed cross coupling reactions alternatives to PtBu3. Chem. Soc. Rev. 39, 694–711 (2010).

    Article  CAS  PubMed  Google Scholar 

  82. Park, N. H., Vinogradova, E. V., Surry, D. S. & Buchwald, S. L. Design of new ligands for the palladium-catalyzed arylation of α-branched secondary amines. Angew. Chem. Int. Ed. 54, 8259–8262 (2015).

    Article  CAS  Google Scholar 

  83. Dennis, J. M., White, N. A., Liu, R. Y. & Buchwald, S. L. Breaking the base barrier: an electron-deficient palladium catalyst enables the use of a common soluble base in C‒N coupling. J. Am. Chem. Soc. 140, 4721–4725 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  84. Wünsche, M. A. et al. Imidazolin-2-ylidenaminophosphines as highly electron-rich ligands for transition-metal catalysts. Angew. Chem. Int. Ed. 54, 11857–11860 (2015).

    Article  Google Scholar 

  85. Rotering, P., Wilm, L. F. B., Werra, J. A. & Dielmann, F. Pyridinylidenaminophosphines: facile access to highly electron-rich phosphines. Chem. Eur. J. 26, 406–411 (2020).

    Article  CAS  PubMed  Google Scholar 

  86. Buß, F., Mehlmann, P., Mück-Lichtenfeld, C., Bergander, K. & Dielmann, F. Reversible carbon dioxide binding by simple Lewis base adducts with electron-rich phosphines. J. Am. Chem. Soc. 138, 1840–1843 (2016).

    Article  PubMed  Google Scholar 

  87. Ullrich, S., Kovačević, B., Xie, X. & Sundermeyer, J. Phosphazenyl phosphines: the most electron‐rich uncharged phosphorus Brønsted and Lewis bases. Angew. Chem. Int. Ed. 58, 10335–10339 (2019).

    Article  CAS  Google Scholar 

  88. Dumrath, A. et al. Recyclable catalysts for palladium-catalyzed C‒O coupling reactions, Buchwald–Hartwig aminations, and Sonogashira reactions. Angew. Chem. Int. Ed. 49, 8988–8992 (2010).

    Article  CAS  Google Scholar 

  89. Dumrath, A., Lübbe, C., Neumann, H., Jackstell, R. & Beller, M. Recyclable catalysts for palladium-catalyzed aminations of aryl halides. Chem. Eur. J. 17, 9599–9604 (2011).

    Article  CAS  PubMed  Google Scholar 

  90. Yu, C.-H. et al. Increasing the donor strength of alkenylphosphines by twisting the C=C double bond. Angew. Chem. Int. Ed. 63, e02416764 (2024).

    Google Scholar 

  91. Scherpf, T. et al. Ylide-functionalized phosphines: strong donor ligands for homogeneous catalysis. Angew. Chem. Int. Ed. 57, 12859–12864 (2018).

    Article  CAS  Google Scholar 

  92. Däschlein-Gessner, V. & Scherpf, T. Ylid-funktionalisierte phosphane zur Verwendung in Metallkomplexen und der homogenen katalyse. Patent WO2019030304A1 (2019).

  93. Issleib, K. & Lindner, R. Beiträge zur Chemie der Phosphinalkylene, III. Zur Basizität und Säurespaltung der Phosphinalkylene. Liebigs Ann. Chem. 707, 120–129 (1967).

    Article  CAS  Google Scholar 

  94. Lapointe, S., Sarbajna, A. & Gessner, V. H. Ylide-substituted phosphines: a platform of strong donor ligands for gold catalysis and palladium-catalyzed coupling reactions. Acc. Chem. Res. 55, 770–782 (2022).

    Article  CAS  PubMed  Google Scholar 

  95. Löffler, J. et al. P,N-coordinating ylide-functionalized phosphines (NYPhos): a ligand platform for the selective monoarylation of small nucleophiles. Angew. Chem. Int. Ed. 63, e202408947 (2024).

    Article  Google Scholar 

  96. Goebel, J. F. et al. Computer-driven development of ylide functionalized phosphines for palladium-catalyzed Hiyama couplings. Angew. Chem. Int. Ed. 62, e202216160 (2023).

    Article  CAS  Google Scholar 

  97. Xiao, Y. et al. Palladium-catalyzed coupling of aryl chlorides with secondary phosphines to construct unsymmetrical tertiary phosphines. Org. Lett. 26, 10564–10569 (2024).

    Article  CAS  PubMed  Google Scholar 

  98. Puerta-Oteo, R., Ojeda-Amador, A. I., Jiménez, M. V. & Pérez-Torrente, J. J. Catalytic applications of zwitterionic transition metal compounds. Dalton Trans. 51, 817–830 (2022).

    Article  CAS  PubMed  Google Scholar 

  99. Stradiotto, M., Cipot, J. & McDonald, R. A catalytically active, charge-neutral Rh(I) zwitterion featuring a P,N-substituted ‘naked’ indenide ligand. J. Am. Chem. Soc. 125, 5618–5619 (2003).

    Article  CAS  PubMed  Google Scholar 

  100. Cipot, J., McDonald, R. & Stradiotto, M. New bidentate cationic and zwitterionic relatives of Crabtree’s hydrogenation catalyst. Chem. Commun. https://doi.org/10.1039/B510253G (2005).

  101. Lundgren, R. J., Rankin, M. A., McDonald, R., Schatte, G. & Stradiotto, M. A formally zwitterionic ruthenium catalyst precursor for the transfer hydrogenation of ketones that does not feature an ancillary ligand N‒H functionality. Angew. Chem. Int. Ed. 46, 4732–4735 (2007).

    Article  CAS  Google Scholar 

  102. Lavallo, V., Wright, J. H. II, Tham, F. S. & Quinlivan, S. Perhalogenated carba-closo-dodecaborate anions as ligand substituents: applications in gold catalysis. Angew. Chem. Int. Ed. 52, 3172–3176 (2013).

    Article  CAS  Google Scholar 

  103. van Leeuwen, P. W. N. M., Cano, I. & Freixa, Z. Secondary phosphine oxides: bifunctional ligands in catalysis. ChemCatChem 12, 3982–3994 (2020).

    Article  Google Scholar 

  104. Ackermann, L. & Born, R. Modular diamino- and dioxophosphine oxides and chlorides as ligands for transition-metal-catalyzed C‒C and C‒N couplings with aryl chlorides. Angew. Chem. Int. Ed. 44, 2444–2447 (2005).

    Article  CAS  Google Scholar 

  105. Martin, D., Moraleda, D., Achard, T., Giordano, L. & Buono, G. Assessment of the electronic properties of P ligands stemming from secondary phosphine oxides, P ligands stemming SPOs. Chem. Eur. J. 17, 12729–12740 (2011).

    Article  CAS  PubMed  Google Scholar 

  106. Bellotti, P., Koy, M., Hopkinson, M. N. & Glorius, F. Recent advances in the chemistry and applications of N-heterocyclic carbenes. Nat. Rev. Chem. 5, 711–725 (2021).

    Article  CAS  PubMed  Google Scholar 

  107. Weetman, C. in Encyclopedia of Inorganic and Bioinorganic Chemistry (ed. Scott, R. A.) 1–27 (Wiley, 2025).

  108. Roy, M. M. D. & Rivard, E. Pushing chemical boundaries with N-heterocyclic olefins (NHOs): from catalysis to main group element chemistry. Acc. Chem. Res. 50, 2017–2025 (2017).

    Article  CAS  PubMed  Google Scholar 

  109. Ghadwal, R. S. Tuning the electronic properties of main-group species by N-heterocyclic vinyl (NHV) scaffolds. Acc. Chem. Res. 55, 457–470 (2022).

    Article  CAS  PubMed  Google Scholar 

  110. Sarbajna, A., Swamy, V. S. V. S. N. & Gessner, V. H. Phosphorus-ylides: powerful substituents for the stabilization of reactive main group compounds. Chem. Sci. 12, 2016–2024 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  111. Ghadwal, R. S., Schürmann, C. J., Andrada, D. M. & Frenking, G. Mono- and di-cationic hydrido boron compounds. Dalton Trans. 44, 14359–14367 (2015).

    Article  CAS  PubMed  Google Scholar 

  112. Lee, W.-H., Lin, Y.-F., Lee, G.-H., Peng, S.-M. & Chiu, C.-W. N-Heterocyclic olefin stabilized boron dication. Dalton Trans. 45, 5937–5940 (2016).

    Article  CAS  PubMed  Google Scholar 

  113. Scherpf, T., Feichtner, K.-S. & Gessner, V. H. Using ylide functionalization to stabilize boron cations. Angew. Chem. Int. Ed. 56, 3275–3279 (2017).

    Article  CAS  Google Scholar 

  114. Krämer, F., Paradies, J., Fernández, I. & Breher, F. A crystalline aluminium-carbon-based ambiphile capable of activation and catalytic transfer of ammonia in non-aqueous media. Nat. Chem. 16, 63–69 (2024).

    Article  PubMed  Google Scholar 

  115. Krämer, F., Paradies, J., Fernández, I. & Breher, F. Quo vadis CO2 activation: catalytic reduction of CO2 to methanol using aluminum and gallium/carbon-based ambiphiles. Chem. Eur. J. 30, e202303380 (2024).

    Article  PubMed  Google Scholar 

  116. Hering-Junghans, C., Andreiuk, P., Ferguson, M. J., McDonald, R. & Rivard, E. Using N-heterocyclic vinyl ligands to access stable divinylgermylenes and a germylium cation. Angew. Chem. Int. Ed. 56, 6272–6275 (2017).

    Article  CAS  Google Scholar 

  117. Asay, M., Inoue, S. & Driess, M. Aromatic ylide-stabilized carbocyclic silylene. Angew. Chem. Int. Ed. 50, 9589–9592 (2011).

    Article  CAS  Google Scholar 

  118. Schmidpeter, A., Schrödel, H.-P. & Knizek, J. 2-stannaindenes and 2-stannaindanes. Heteroat. Chem. 9, 103–108 (1998).

    Article  CAS  Google Scholar 

  119. Alvarado-Beltran, I., Baceiredo, A., Saffon-Merceron, N., Branchadell, V. & Kato, T. Cyclic amino(ylide) silylene: a stable heterocyclic silylene with strongly electron-donating character. Angew. Chem. Int. Ed. 55, 16141–16144 (2016).

    Article  CAS  Google Scholar 

  120. Mohapatra, C. et al. Isolation of a diylide-stabilized stannylene and germylene: enhanced donor strength through coplanar lone pair alignment. Angew. Chem. Int. Ed. Engl. 58, 7459–7463 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  121. Li, Z. et al. (L)2C2P2: dicarbondiphosphide stabilized by N-heterocyclic carbenes or cyclic diamido carbenes. Angew. Chem. Int. Ed. 56, 5744–5749 (2017).

    Article  CAS  Google Scholar 

  122. Sharma, M. K. et al. Isolation of a Ge(I) diradicaloid and dihydrogen splitting. J. Am. Chem. Soc. 143, 121–125 (2021).

    Article  CAS  PubMed  Google Scholar 

  123. Sharma, M. K. et al. An open-shell singlet Sn(I) diradical and H2 splitting. Angew. Chem. Int. Ed. 60, 6414–6418 (2021).

    Article  CAS  Google Scholar 

  124. Riddlestone, I. M., Kraft, A., Schaefer, J. & Krossing, I. Taming the cationic beast: novel developments in the synthesis and application of weakly coordinating anions. Angew. Chem. Int. Ed. 57, 13982–14024 (2018).

    Article  CAS  Google Scholar 

  125. Fisher, S. P. et al. Nonclassical applications of closo-carborane anions: from main group chemistry and catalysis to energy storage. Chem. Rev. 119, 8262–8290 (2019).

    Article  CAS  PubMed  Google Scholar 

  126. Li, Y., Cokoja, M. & Kühn, F. E. Inorganic/organometallic catalysts and initiators involving weakly coordinating anions for isobutene polymerisation. Coord. Chem. Rev. 255, 1541–1557 (2011).

    Article  CAS  Google Scholar 

  127. Engesser, T. A., Lichtenthaler, M. R., Schleep, M. & Krossing, I. Reactive p-block cations stabilized by weakly coordinating anions. Chem. Soc. Rev. 45, 789–899 (2016).

    Article  CAS  PubMed  Google Scholar 

  128. Mandouma, G., Collins, J. & Williams, D. Synthesis, crystal structure, and conductivity of a weakly coordinating anion/cation salt for electrolyte application in next-generation batteries. Acc. Chem. Res. 56, 1263–1270 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  129. Rupp, A. B. A. & Krossing, I. Ionic liquids with weakly coordinating [MIII(ORF)4]− anions. Acc. Chem. Res. 48, 2537–2546 (2015).

    Article  CAS  PubMed  Google Scholar 

  130. Niemann, M., Neumann, B., Stammler, H.-G. & Hoge, B. Synthesis, properties, and application of tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)4]. Angew. Chem. Int. Ed. 58, 8938–8942 (2019).

    Article  CAS  Google Scholar 

  131. Martens, A. et al. Facile and systematic access to the least-coordinating WCA [(RFO)3Al-F-Al(ORF)3]− and its more Lewis-basic brother [F-Al(ORF)3]− (RF = C(CF3)3). Chem. Sci. 9, 7058–7068 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  132. Olaru, M. et al. The weakly coordinating tris(trichlorosilyl)silyl anion. Angew. Chem. Int. Ed. 56, 16490 (2017).

    Article  CAS  Google Scholar 

  133. Knüpfer, C., Klerner, L., Mai, J., Langer, J. & Harder, S. s-Block metal complexes of superbulky (tBu3Si)2N−: a new weakly coordinating anion? Chem. Sci. 15, 4386–4395 (2024).

    Article  PubMed  PubMed Central  Google Scholar 

  134. Wiesner, A., Gries, T. W., Steinhauer, S., Beckers, H. & Riedel, S. Superacids based on pentafluoroorthotellurate derivatives of aluminum. Angew. Chem. Int. Ed. 56, 8263–8266 (2017).

    Article  CAS  Google Scholar 

  135. Golden, J. H., Mutolo, P. F., Lobkovsky, E. B. & DiSalvo, F. J. Lithium-mediated organofluorine hydrogen bonding: structure of lithium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate tetrahydrate. Inorg. Chem. 33, 5374–5375 (1994).

    Article  CAS  Google Scholar 

  136. Krossing, I. The facile preparation of weakly coordinating anions: structure and characterisation of silverpolyfluoroalkoxyaluminates AgAl(ORF)4, calculation of the alkoxide ion affinity. Chem. Eur. J. 7, 490–502 (2001).

    Article  CAS  PubMed  Google Scholar 

  137. Shelly, K., Reed, C. A., Lee, Y. J. & Scheidt, W. R. The least coordinating anion. J. Am. Chem. Soc. 108, 3117–3118 (1986).

    Article  CAS  Google Scholar 

  138. Unkrig, W., Schmitt, M., Kratzert, D., Himmel, D. & Krossing, I. Synthesis and characterization of crystalline niobium and tantalum carbonyl complexes at room temperature. Nat. Chem. 12, 647–653 (2020).

    Article  CAS  PubMed  Google Scholar 

  139. Sellin, M. et al. Utilizing the perfluoronaphthalene radical cation as a selective deelectronator to access a variety of strongly oxidizing reactive cations. Angew. Chem. Int. Ed. 63, e202406742 (2024).

    Article  CAS  Google Scholar 

  140. Willrett, J. et al. Synthesis and characterization of a copper dinitrogen complex supported by a weakly coordinating anion. Angew. Chem. Int. Ed. 63, e202405330 (2024).

    Article  CAS  Google Scholar 

  141. Yang, X. et al. Synthesis, isolation, and characterization of two cationic organobismuth(II) pincer complexes relevant in radical redox chemistry. J. Am. Chem. Soc. 145, 5618–5623 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  142. Klare, H. F. T. et al. Silylium ions: from elusive reactive intermediates to potent catalysts. Chem. Rev. 121, 5889–5985 (2021).

    Article  CAS  PubMed  Google Scholar 

  143. Wasserscheid, P. & Welton, T. (eds) Ionic Liquids in Synthesis (Wiley, 2007).

  144. Aravindan, V., Gnanaraj, J., Madhavi, S. & Liu, H.-K. Lithium-ion conducting electrolyte salts for lithium batteries. Chem. Eur. J. 17, 14326–14346 (2011).

    Article  CAS  PubMed  Google Scholar 

  145. Turowsky, L. & Seppelt, K. Tris[(trifluoromethyl)sulfonyl]methane, HC(SO2CF3)3. Inorg. Chem. 27, 2135–2137 (1988).

    Article  CAS  Google Scholar 

  146. Schulz, C., Daniels, J., Bredow, T. & Beck, J. The electrochemical synthesis of polycationic clusters. Angew. Chem. Int. Ed. 55, 1173–1177 (2016).

    Article  CAS  Google Scholar 

  147. Murmann, P. et al. Electrochemical performance and thermal stability studies of two lithium sulfonyl methide salts in lithium-ion battery electrolytes. J. Electrochem. Soc. 162, A1738–A1744 (2015).

    Article  CAS  Google Scholar 

  148. Siedle, A. R., Newmark, R. A. & Gleason, W. B. Facile addition and elimination reactions of fluorocarbon acids at platinum. J. Am. Chem. Soc. 108, 767–773 (1986).

    Article  CAS  Google Scholar 

  149. Ishihara, K., Hasegawa, A. & Yamamoto, H. Polystyrene-bound tetrafluorophenylbis(triflyl)methane as an organic-solvent-swellable and strong Brønsted acid catalyst. Angew. Chem. Int. Ed. 40, 4077–4079 (2001).

    Article  CAS  Google Scholar 

  150. Höfler, D. et al. 1,1,3,3‐Tetratriflylpropene (TTP): a strong, allylic C–H acid for Brønsted and Lewis acid catalysis. Angew. Chem. Int. Ed. 56, 1411–1415 (2017).

    Article  Google Scholar 

  151. Gatzenmeier, T. et al. Asymmetric Lewis acid organocatalysis of the Diels–Alder reaction by a silylated C‒H acid. Science 351, 949–952 (2016).

    Article  CAS  PubMed  Google Scholar 

  152. Popovic, J. et al. High lithium transference number electrolytes containing tetratriflylpropene’s lithium salt. J. Phys. Chem. Lett. 9, 5116–5120 (2018).

    Article  CAS  PubMed  Google Scholar 

  153. Kelling, L., Eßer, J., Knyszek, D. & Gessner, V. H. Carbon-based weakly coordinating anions: molecular design, synthesis and applications. Angew. Chem. Int. Ed. 63, e202405936 (2024).

    Article  CAS  Google Scholar 

  154. Chambers, R. D. et al. Reactions involving fluoride ion. Part 41.1,2 Synthesis of hexakis(trifluoromethyl) cyclopentadiene and derived cyclopentadienide salts. J. Chem. Soc. Perkin Trans. 1, 135–146 (1997).

    Article  Google Scholar 

  155. Sievers, R., Sellin, M., Rupf, S. M., Parche, J. & Malischewski, M. Introducing perfluorinated Cp* ligand coordination chemistry. Angew. Chem. Int. Ed. 61, e202211147 (2022).

    Article  CAS  Google Scholar 

  156. Schulte, Y. et al. Structural characterization and reactivity of a room-temperature-stable, antiaromatic cyclopentadienyl cation salt. Nat. Chem. 16, 651–657 (2024).

    Article  CAS  PubMed  Google Scholar 

  157. Akiyama, T. Stronger Brønsted acids. Chem. Rev. 107, 5744–5758 (2007).

    Article  CAS  PubMed  Google Scholar 

  158. Cheon, C. H. & Yamamoto, H. Super Brønsted acid catalysis. Chem. Commun. 47, 3043–3056 (2011).

    Article  CAS  Google Scholar 

  159. Yanai, H. & Taguchi, T. Synthesis of superacidic carbon acid and its derivatives. J. Fluor. Chem. 174, 108–119 (2015).

    Article  CAS  Google Scholar 

  160. Nakashima, D. & Yamamoto, H. Design of chiral N-triflyl phosphoramide as a strong chiral Brønsted acid and its application to asymmetric Diels−Alder reaction. J. Am. Chem. Soc. 128, 9626–9627 (2006).

    Article  CAS  PubMed  Google Scholar 

  161. Cheon, C. H. & Yamamoto, H. Development of N,N-bis(perfluoroalkanesulfonyl)squaramides as new strong Brønsted acids and their application to organic reactions. Tetrahedron 66, 4257–4264 (2010).

    Article  CAS  Google Scholar 

  162. Akiyama, T., Itoh, J., Yokota, K. & Fuchibe, K. Enantioselective Mannich-type reaction catalyzed by a chiral Brønsted acid. Angew. Chem. Int. Ed. 43, 1566–1568 (2004).

    Article  CAS  Google Scholar 

  163. Uraguchi, D. & Terada, M. Chiral Brønsted acid-catalyzed direct Mannich reactions via electrophilic activation. J. Am. Chem. Soc. 126, 5356–5357 (2004).

    Article  CAS  PubMed  Google Scholar 

  164. Akiyama, T., Itoh, J. & Fuchibe, K. Recent progress in chiral Brønsted acid catalysis. Adv. Synth. Catal. 348, 999–1010 (2006).

    Article  CAS  Google Scholar 

  165. Čorić, I. & List, B. Asymmetric spiroacetalization catalysed by confined Brønsted acids. Nature 483, 315–319 (2012).

    Article  PubMed  Google Scholar 

  166. Schwengers, S. A. et al. Unified approach to imidodiphosphate-type Brønsted acids with tunable confinement and acidity. J. Am. Chem. Soc. 143, 14835–14844 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  167. Schreyer, L., Properzi, R. & List, B. IDPi catalysis. Angew. Chem. Int. Ed. 58, 12761–12777 (2019).

    Article  CAS  Google Scholar 

  168. Yanai, H. et al. 2-(Pyridinium-1-yl)-1,1-bis(perfluoroalkylsulfonyl)ethan-1-ide: a practical reagent for synthesis of strongly acidic 1,1-bis(perfluoroalkylsulfonyl)alkanes. Chem. Eur. J. 23, 8203–8211 (2017).

    Article  CAS  PubMed  Google Scholar 

  169. Hasegawa, A., Naganawa, Y., Fushimi, M., Ishihara, K. & Yamamoto, H. Design of Brønsted acid-assisted chiral Brønsted acid catalyst bearing a bis(triflyl)methyl group for a Mannich-type reaction. Org. Lett. 8, 3175–3178 (2006).

    Article  CAS  PubMed  Google Scholar 

  170. Peng, B. et al. A powerful chiral super Brønsted C–H acid for asymmetric catalysis. J. Am. Chem. Soc. 144, 2853–2860 (2022).

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy — EXC-2033 - 390677874 — RESOLV and INST 213/917-1 FUGG, as well as the European Union (ERC, CarbFunction, 101086951). A.D. thanks the Alexander von Humboldt Foundation for a postdoctoral research fellowship. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them.

Author information

Author notes

  1. These authors contributed equally: Arpan Das, Quentin Le Dé.

Authors and Affiliations

  1. Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Bochum, Germany

    Arpan Das, Quentin Le Dé & Viktoria H. Gessner

Authors
  1. Arpan Das
    View author publications

    Search author on:PubMed Google Scholar

  2. Quentin Le Dé
    View author publications

    Search author on:PubMed Google Scholar

  3. Viktoria H. Gessner
    View author publications

    Search author on:PubMed Google Scholar

Contributions

All authors wrote the article. V.H.G. finalized the manuscript.

Corresponding author

Correspondence to Viktoria H. Gessner.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Reviews Chemistry thanks Robert Mulvey and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Das, A., Le Dé, Q. & Gessner, V.H. Rethinking carbanion chemistry from donor substituents to weakly coordinating carbanions. Nat Rev Chem 9, 523–536 (2025). https://doi.org/10.1038/s41570-025-00725-3

Download citation

  • Accepted:

  • Published:

  • Version of record:

  • Issue date:

  • DOI: https://doi.org/10.1038/s41570-025-00725-3

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing