Copper-Catalyzed Synthesis of 1,1-Diborylalkanes through Regioselective Dihydroboration of Terminal Alkynes

The copper‐catalyzed sequential hydroboration of terminal alkynes with pinacolborane to prepare 1,1‐diborylalkanes directly from alkynes was studied. Protected propargyl amines, propargyl alcohol derivatives, and simple alkynes regioselectively produced the desired 1,1‐diborylalkanes in good yields with a copper/xantphos catalyst. Copper on call: The copper‐catalyzed sequential regioselective hydroboration of terminal alkynes with pinacolborane provided 1,1‐diborylalkanes directly from alkynes. Protected propargyl amines, propargyl alcohol derivatives, and simple alkynes reacted to give the desired 1,1‐diborylalkanes in good yields with a copper/xantphos catalyst.