S-Trifluoromethyl thioesters as bifunctional reagents for acyl-trifluoromethylthiolation of alkenes and 1,3-enynes via photoredox/copper dual catalysis

Abstract

The difunctionalization of unsaturated compounds offers great advantages regarding step- and atom-economy for the construction of various vicinal functional groups. Introducing acyl and trifluoromethylthio groups into compounds simultaneously still remains a challenge. Using S-trifluoromethyl thioesters as bifunctional reagents, we developed photoredox/copper dual-catalyzed 1,2-acyl-trifluoromethylthiolation of alkenes and 1,4-acyl-trifluoromethylthiolation of 1,3-enynes. β-Trifluoromethylthiolated ketones and δ-trifluoromethylthiolated β-allenyl ketones can be obtained in moderate to good yields with broad functional group compatibility. More broadly, by combining S-trifluoromethyl thioesters with other radical precursors, trifluoromethylthio-fluoroalkylation and trifluoromethylthio-arylation of alkenes could be realized, respectively.