Convenient peripheral aroyloxylation reactions of porphyrins and chlorophyll-a-based chlorins with benzoyl peroxide

A practical and efficient methodology for the formation of C-O bonds on the porphyrin/chlorin periphery was developed. The aroyloxy-substituted porphyrins and chlorins related to chlorophyll-a at the β- and meso-positions, respectively, were conveniently synthesized by the free radical substitution reaction with benzoyl peroxide and its homologs.