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 organophotocatalyst 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.