Fluorinated Reagents in Organic Synthesis

Fluorinated reagents have become integral to modern organic synthesis owing to the unique properties imparted by carbon–fluorine bonds, including enhanced metabolic stability, lipophilicity and electronic effects. Acyl fluorides, fluoro-carbonyl precursors and trifluoromethylating agents enable the introduction of fluorine or fluoroalkyl motifs under mild conditions, expanding the toolkit for late-stage functionalisation of complex molecules. Developments in transition-metal catalysis, redox cooperative systems and metal-free protocols have overcome longstanding challenges in handling reactive intermediates such as formyl fluoride or difluorocarbene equivalents. These advances drive applications across pharmaceuticals, agrochemicals and materials, where fluorine incorporation can fine-tune biological activity, thermal stability and optical properties. In particular, bench-stable reagents and one-pot sequences now allow chemists to access diverse fluorinated scaffolds without reliance on hazardous gases or stoichiometric metal-fluoride additives.

Research from Nature Portfolio

Recent studies have harnessed palladium catalysis in conjunction with phosphine ligands to achieve direct fluorocarbonylation of organoboron substrates. A synergistic redox cycle between Pd(II)/(0) and P(III)/(V) enables insertion of a fluoro-carbonyl unit derived from a bench-stable trifluoromethyl arylsulfonate, delivering aryl and alkyl acyl fluorides under mild, functional-group-tolerant conditions. Mechanistic investigations including X-ray crystallography and NMR spectroscopy elucidate key Pd–OCF3 intermediates. Complementary work demonstrates carbonylation of aryl, vinyl and heteroaryl iodides using a solid difluoromethoxy-pyridine reagent as a surrogate for gaseous formyl fluoride. This approach furnishes high yields of acyl fluorides across a broad substrate scope and can be telescoped into one-pot amidation, facilitating late-stage modification of bioactive molecules without external CO or hazardous reagents.

Fluorinated Reagents in Organic Synthesis publication trend

The graph below shows the total number of articles in fluorinated reagents in organic synthesis across all publications each year (not limited to Nature Index journals).

Technical terms

Acyl fluoride: A functional group featuring a carbonyl bonded to fluorine, valued as a reactive yet isolable acylating agent.

Fluorocarbonylation: The incorporation of a fluoro-carbonyl unit (–COF) into an organic substrate, often via transition-metal catalysis.

Trifluoromethylation: Introduction of a –CF3 group into an organic molecule, enhancing lipophilicity and metabolic stability.

Decarbonylation: A transformation in which a carbonyl fragment (CO) is expelled from a substrate, frequently employed in metal-catalysed cross-couplings.

Deoxyfluorination: Replacement of a hydroxyl or carbonyl oxygen with fluorine, typically using specialised reagents to afford C–F bonds.

References

1. Fluorocarbonylation via palladium/phosphine synergistic catalysis. Nature Communications (2023).
2. Pd-catalyzed fluoro-carbonylation of aryl, vinyl, and heteroaryl iodides using 2-(difluoromethoxy)-5-nitropyridine. Communications Chemistry (2020).
3. Palladium‐Catalyzed Decarbonylative Trifluoromethylation of Acid Fluorides. Angewandte Chemie International Edition (2018).
4. Visible-light induced transition-metal and photosensitizer-free conversion of aldehydes to acyl fluorides under mild conditions. Green Synthesis and Catalysis (2022).
5. Carboxylic Acid Deoxyfluorination and One-Pot Amide Bond Formation Using Pentafluoropyridine (PFP). Organic Letters (2021).