Copper-Catalyzed Regioselective Dihydroboration of Alkynes to Construct gem-Diborylalkanes

We develop herein an efficient copper-catalyzed dihydroboration of alkynes with HBpin to synthesize gem-diborylalkanes. This catalytic process features a broad substrate scope, good functional group tolerance, and excellent regioselectivity. Notably, the gram-scale reaction and further product derivatizations demonstrate the practicality of this protocol. Preliminary mechanistic studies indicate that the process involves the hydroboration of the alkyne and the vinylboronate intermediate.