Visible-light-induced radical difluoromethylation/cyclization of biarylvinyl azides: Facile access to CF2H-labelled phenanthridines

Abstract

The direct difluoromethylation/cyclization of biarylvinyl azides with easily accessible [bis(difluoroacetoxy)iodo]benzene is achieved by visible-light-mediated radical difluoromethylation/iminyl cyclization process under mild conditions. The reaction initiates the decarboxylation of difluoromethyl carboxylic acids through light-induced the homolytic cleavage of [bis(difluoroacetoxy)iodo]benzene and affords a series of difluoromethyl functionalized phenanthridines in moderate to good yields. This strategy has the advantages of simple and readily available materials and transition metal-free conditions, thus boding well for the widespread applications of this method in medical and synthetic chemistry.