Photocatalytic synthesis of polyfluoroalkylated dihydropyrazoles and tetrahydropyridazines

Abstract

A photocatalytic trifluoromethylation/cyclization reaction of N-allyl and N-homoallyl aldehyde hydrazones with trifluoromethyl thianthrenium triflate was developed for the synthesis of trifluoromethylated dihydropyrazoles and tetrahydropyridazines. Besides, PhI(O₂CCHF₂)₂ was employed to realize the construction of difluoromethylated dihydropyrazoles and tetrahydropyridazines. These protocols exhibit a broad substrate scope and good functional group tolerance.