Copper(I)-Catalyzed Stereo- and Chemoselective Borylative Radical Cyclization of Alkyl Halides Bearing an Alkene Moiety

The stereoselective borylative radical cyclization of alkyl halides containing an alkene moiety was developed using a copper­(I)/diboron catalyst system. The optimized reaction conditions allowed us to control the chemoselectivity between the allylic substitution and the borylative radical cyclization. The borylation products were subsequently converted to highly functionalized organic compounds by derivatization of the newly formed C–B bond. This borylative radical cyclization offers a novel methodology for the stereoselective synthesis of various heterocyclic compounds.