Visible light-mediated organocatalyzed 1,3-aminoacylation of cyclopropane employing N-benzoyl saccharin as bifunctional reagent

The carboamination of unsaturated molecules using bifunctional reagents is considered an attractive approach for the synthesis of nitrogen-containing compounds. However, bifunctional C–N reagents have never been employed in the carboamination of cyclopropane. In this study, we use an N-heterocyclic carbene (NHC), N-benzoyl saccharin, as a bifunctional reagent and a photoredox catalyst for a dual-catalyzed 1,3-aminoacylation of cyclopropane. NHCs play multiple roles, functioning as Lewis base catalysts to activate C–N bonds, promoting the oxidative quenching process of PC*, and acting as efficient acyl radical transfer catalysts for the formation of C–C bonds. The oxidative quenching process between the excited-state PC* and acyl NHC adduct is the key to the photooxidation generality of aryl cyclopropanes. The carboamination of unsaturated molecules with bifunctional carboamination reagents is considered to be an attractive approach for the synthesis of nitrogen-containing compounds but employing bifunctional C–N reagents in the functionalization of cyclopropane remains underdeveloped. Here the authors present N-heterocyclic carbenes and a photoredox catalyst dualcatalyzed 1,3-aminoacylation of cyclopropane employing N-benzoyl saccharin as a bifunctional reagent.