Transition-Metal-Catalyzed Synthesis of Chiral Allylboronates†

Since the pioneering work on Cr(III)-catalyzed enantioselective [4+2]/allylboration reported by Hall and co-workers, a variety of catalytic methodologies for the asymmetric allylic borylation reactions have been developed to provide chiral allylboronates bearing a wide range of functional groups. This review article describes recent advances in transition-metal catalyzed preparation of chiral allylboronates, especially on those in the past three years, and with the emphasis on the aspect of asymmetric catalysis. According to the mechanism of achieving the chemo-, regio-, stereo- and enantioselectivities, the discussion is divided in two parts: substrate-controlled and catalyst-controlled synthesis.