Anti-selective Asymmetric Henry Reaction Catalyzed By A Chira Heterobimetallic Cu-Sm Complex

The products of asymmetric Henry reaction,?-nitro alcohols,are important chiral intermediates.They are widely used in the synthesis of a variety of chiral medicines,agricultural chemicals and chiral ligands.Thus,the asymmetric Henry reaction attracts many scientists and excellent results have been achieved.However,the asymmetric Henry reaction of nitroethane has always been a problem with weak reactivity and low diastereoselectivity.In order to solve this problem,a novel chiral heterobimetallic Cu-Sm complex has been developed by a convenient one-pot method for the anti-selective asymmetric Henry reaction.After a series of optimized conditions,we conducted a substrate extension under optimal conditions.The results showed that the catalytic system had good chiral induction for aromatic aldehydes and heterocyclic aldehydes.The anti-products are obtained in up to 99% yield,>30:1 dr,and 98% ee.The results of control experiments and ESI-MS analysis of the complex indicate that the monomericbimetallic Cu/Sm/1 complex would be the active species.On the basis of this,four possible reaction transition states were proposed,taking into account the effects of steric hindrance and electron effects,we deduced that the product configuration is anti-(1S,2R),which is consistent with the actual product configuration.