Employed in organic synthesis. Addition of catecholborane to vinylarenes in the presence of Wilkinson's catalyst, gives Markovnikov hydroboration products exclusively, whereas the corresponding reaction with a-substituted vinylarenesgivesgood yields of vinylboronate. Hydroboration with catecholborane, followed by treatment with easily available reagents such as alkenyl sulfones or alkynyl phenyl sulfones in the presence of a radical initiator, represents an effective and simple one-pot procedure for direct vinylation, formylation, and cyanation. Catecholborane may be used as a stereoselective reducing agent when converting β-hydroxy ketones to syn 1,3-diols.
