Recyclable Cu/g-C3N4 nanometric semiconductor catalyzed N-formylation of amines via photocatalytic aerobic oxidative C–C bond cleavage of aldehydes under visible-light irradiation

Due to its difficulty and complexity,the cleavage and subsequent functionalization of the C(sp3)-C(sp3) single bond has received less attention than the C–C bond formation reactions that have been extensively studied.Herein,by utilizing Cu/g-C3N4nanometric semiconductor as a recyclable photocatalyst,an aerobic oxidative C–C bond cleavage of aldehydes was developed with the promotion of amines under visible light irradiation.Based on the reaction,phenylacetaldehyde was selected as a highly efficient formylation reagent for amines.Under blue light irradiation,good to excellent yields of formamides were achieved for various amines in 1 atm oxygen atmosphere at room temperature.This methodology offers a practical,neutral and gentle alternative to the preparation of formamides.