Oxidative Functionalization of Cinnamaldehyde Derivatives: Control of Chemoselectivity by Organophotocatalysis and Dual Organocatalysis

The catalytic and chemoselective oxidation of cinnamaldehyde derivatives having a C=C bond and formyl group was studied by using two organocatalysts. The visible light-induced catalysis using rhodamine 6G as an organo-photocatalyst promoted the methoxyhydroxylation of the C=C bond in a chemoselective manner. In contrast, the cooperation between rhodamine 6G and N-heterocyclic carbene (NHC) allowed the oxidative esterification of formyl group.