Asymmetric Synthesis of SCF3-Substituted Alkylboronates by Copper-Catalyzed Hydroboration of 1-Trifluoromethylthioalkenes

Abstract

A synthetic method for preparation of optically active trifluoromethylthio (SCF₃) compounds by a copper-catalyzed regio- and enantioselective hydroboration of 1-trifluoromethylthioalkenes with H-Bpin has been developed. The enantioselective hydrocupration of an in situ generated CuH species and subsequent boration reaction generate a chiral SCF₃-containing alkylboronate, of which Bpin moiety can be further transformed to deliver various optically active SCF₃ molecules. Computational studies suggest that the SCF₃ group successfully controls the regioselectivity in the reaction.

Keywords: asymmetric catalysis; copper; fluorine molecule; hydrofunctionalization; trifluoromethylthio group.