Photocatalytic decarboxylation of free carboxylic acids and their functionalization

Abstract

Visible light mediated decarboxylative functionalization of carboxylic acids and their derivatives have recently emerged as a novel and powerful toolkit for small molecule activation in diverse carbon-carbon and carbon-hetero bond forming reactions. Naturally abundant highly functionalized bench-stable carboxylic acid analogs have been employed as a promising alternative of non-trivial organometallic reagents for mild and eco-benign synthetic transformation with traceless CO2 by-product. In this highlight article, we focus on the development of various photodecarboxylative functionalization along with intra/inter-molecular cyclization via concerted single electron transfer (SET) or energy transfer (ET) pathway. Moreover, widely explored carboxylic acids are systematically classified here into four parts; i.e., α-keto, aliphatic, α, β-unsaturated, and aromatic analogs for concise overview to the readership. The association of decarboxylative radical species with coupling partner to construct C-C and C-N/O/S/P/X bonds for each analogous acid have been presented in brief.