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.