Asymmetric Catalytic Meerwein-Ponndorf-Verley Reduction of Ketones with Aluminum(III)-VANOL Catalysts

We report herein an efficient aluminum-catalyzed asymmetric MPV reduction of ketones with broad substrate and excellent yields and enantiomeric inductions. A variety of aromatic (both electron-poor and electron-rich) and aliphatic ketones were converted to chiral alcohols in good yields with high enantioselectivities (26 examples, 70-98% yield and 82-99% ee). This method operates under mild conditions (-10 degrees C) and low catalyst loading (1-5 mol %). Furthermore, this process is catalyzed by the earth-abundant main-group element aluminum and employs 2-propanol as the hydride source.