Photocarboxylation of Benzylic C-H Bonds.

ABSTRACT: The carboxylation of sp³-hybridized C-H bonds with CO₂ is a challenging transformation. Herein, we report a visible-light-mediated carboxylation of benzylic C-H bonds with CO₂ into 2-arylpropionic acids under metal-free conditions. Photo-oxidized triisopropylsilanethiol was used as the hydrogen atom transfer catalyst to afford a benzylic radical that accepts an electron from the reduced form of 2,3,4,6-tetra(9H-carbazol-9-yl)-5-(1-phenylethyl)benzonitrile generated in situ. The resulting benzylic carbanion reacts with CO₂ to generate the corresponding carboxylic acid after protonation. The reaction proceeded without the addition of any sacrificial electron donor, electron acceptor or stoichiometric additives. Moderate to good yields of the

SUBMITTER: Meng QY 

PROVIDER: S-EPMC6686948 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature