Carbon-Heteroatom Bond Formation via Photoinduced Decarboxylative Radical Coupling Reactions

Carboxylic acids are among the most widely used and versatile feedstock chemicals in organic synthesis. The generation of alkyl and aryl radicals through decarboxylation has emerged as a valuable strategy for the formation of both C-C and C-heteroatom bonds. Nevertheless, many reported protocols still rely on prior activation of carboxylic acids, which limits their cost-effectiveness and compromises environmental sustainability. This review aims to provide a comprehensive and critical overview of photoinduced decarboxylative coupling reactions employing free carboxylic acids as radical precursors for C-heteroatom bond formation. Particular emphasis is placed on the mechanistic insights underpinning these transformations, along with a discussion of their respective advantages, limitations, and potential for further development. By delineating the progress achieved thus far, we hope to stimulate continued innovation toward more sustainable, efficient, and broadly applicable decarboxylative coupling strategies.