Rh-catalyzed Asymmetric Hydrogenation Of New Enamides And Enol Esters

As the key building blocks of important pharmaceuticals and bioactive compounds,the ?-chiral primary amines and alcohols and their asymmetric synthesis have attracted many research attentions.The traditional synthetic method via asymmetric catalytic hydrogenation of allylic amines/amides and alcohols/esters is relatively difficult and having the problem of low activities,unsatisfied enantioselectivities and limited substrate scopes.Based on the research background of our research group in the aspect of asymmetric catalytic hydrogenation,the asymmetric catalytic hydrogenation of two new kind of ?,?-disubstituted enamides and enol esters was studied for the effective synthesis of ?-chiral primary amines and alcohols.Firstly,a series of substrates with single E or Z configurations were synthesized by stereoselective transformations.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 was evaluated.Catalyzed by a rhodium complex of SDP and SKP,asymmetric hydrogenation of ?,?-disubstituted enamides and enol esters was realized for the first time,a series of ?-chiral primary amines and alcohols bearing acyl groups were synthesized with good yields and enantioselectivities.It provides a practical and novel method for the synthesis of related chiral drugs processing the skeleton of ?-chiral primary amines and alcohols.Therefore,this research has high practical value and theoretical significance.