Cobalt-catalyzedreductivealkynylationtoconstructC（sp）-C（sp3）andC（sp）-C（sp2）bonds

Transition-metal-catalyzed cross-electrophile coupling has emerged as a reliable method for constructing carbon–carbon bonds. Herein, we report a general method, cobalt-catalyzed reductive alkynylation, to construct C（sp）-C（sp3） and C（sp）-C（sp2） bonds. This presented reaction has a broad substrate scope,enabling the efficient cross-electrophile coupling between alkynyl bromides with alkyl halides and aryl or alkenyl（pseudo）halides. This presented reaction is conducted under mild conditions, tolerating many functional groups, thus suitable for the modification and synthesis of biologically active molecules.