(LiOBu)-Bu- t -Promoted trans-Stereoselective and & beta;-Regioselective Hydroboration of Propargyl Alcohols

A convenient and efficient trans-stereoselectiveand & beta;-regioselective hydroboration of propargyl alcohols wasachieved simply with (LiOBu)-Bu- t as the baseand (Bpin)(2) as the boron reagent in dimethyl sulfoxideat room temperature. Both terminal and internal propargyl alcoholswith diverse structures and functional groups underwent the transformationsmoothly to produce & beta;-Bpin-substituted (E)-allylicalcohols, of which the synthetic potentials were demonstrated by thedownstream conversions of boronate, alkenyl, and hydroxyl groups.