Commercially available neat organozincs as highly reactive reagents for catalytic enantioselective addition to ketones and aldehydes under solvent free conditions

Neat Et₂Zn, Ph₂Zn, and highly concentrated Me₂Zn are highly reactive organozinc reagents, which are commercially available in bulk quantities. We here report a catalytic enantioselective Et₂Zn, Ph₂Zn, and Me₂Zn addition to ketones and aldehydes under solvent free or highly concentrated conditions without Ti(Oi-Pr)₄ as a conventional activator of organozinc reagents. The desired optically active tertiary and secondary alcohols were obtained in good yield with high enantioselectivity when compared to the conventional solvent-use conditions. From the viewpoint of ecological and environmental reasons in green chemistry, this catalysis would be practical for not only academic but also industrial use.