Rh-catalyzed Asymmetric Hydrogenative Of Racemic Aldimines Via Dynamic Kinetic Resolution

As the key building blocks of important pharmaceuticals and bioactive compounds such as clopidogrel,prasugrel,vicagrel and aprepitant,the asymmetric synthesis of chiral arylglycines has important application value.The traditional synthetic method via asymmetric catalytic hydrogenation of aryl-acyl imines is relatively difficult,requiring separation of the Z/E isomers and having the problem of low activity.Based on the research background of our research group in the aspect of asymmetric catalytic hydrogenation,racemic aldimines was chosen as the substrate of asymmetric catalytic hydrogenation,and chiral arylglycines was synthesized via dynamic kinetic resolution in this paper.Firstly,a series of substrates of racemic aldimines were synthesized by racemic arylglycines and aryl aldehydes.Secondly,the conditions for asymmetric catalytic hydrogenation of such substrates were determined after a comprehensive and detailed research.Finally,under the optimized conditions,the substrate scope of the asymmetric catalytic hydrogenation via dynamic kinetic resolution was evaluated.Catalyzed by a rhodium complex of P-stereogenic diphosphine ligand trichickenfootphos(TCFP),asymmetric hydrogenation of racemic aldimines via dynamic kinetic resolution was realized for the first time,a series of chiral arylglycines were synthesized with good yields and enantioselectivities.It provides a practical and feasible method for the synthesis of chiral arylglycine compounds and related chiral drugs.Therefore,this research has high practical value and theoretical significance.