Copper-Catalyzed Stereospecific Hydroboration of Internal Allylic Alcohols

An effective Cu-catalyzed stereospecific hydroboration of aliphatic and aromatic 1,1,2-trisubstituted internal allylic alcohols has been reported. This reaction proceeds via a silyl ether transient protection of allylic alcohols and subsequent stereospecific hydroboration. Followed by an oxidative workup, an array of acyclic, cyclic, and heterocyclic 1,3-diols was synthesized in good to excellent yields with good functional group tolerance and excellent diastereomeric ratios (> 20:1).