Synthesis Of Axially Chiral Binol Diamides And Research On Catalytic Asymmetric Michael Addition Reactions

C2 axially chiral compounds catalysts owing to their uni que structure and excellent catalytic properties,as one ki nd of important organocatalysts for carbon-carbon bond form ation reactions,has been investigated extensively in vriou s asymmetric reactions.In particular,C2 axially chiral co mpounds organocatalystshave exhibit excellent enantiosclect ivity in asymmetric Michael addition of 1,3-dicarbonyl comp ounds to ?-nitroalkenes.The Michael adducts of pyrazolin-5-one derivatives to ?-nitroalkenes were used as important s tarting materials and intermediates in the asymmetric synth.esis of chiral biologically active compounds,pesticides and natural products.A novel and effective C2 axially chiral c atalysts were designedand synthesized and applied into a lo t of asymmetric reactions,such as Michael addition,BaylisHillman reaction,Aldol reaction for further realize import ant industrialization.We report a new class of C2 axially chiral amide catalys ts catalyzed asymmetric Michael addition of Pyrazolin-5-one s to ?-nitroalkenes.Different parameters were tested to in dicate the appropriate reaction conditions like catalyst lo ading,solvent,temperature and additives.Under the optimized conditions(at 25?,using CHCl3 as the solvent,50mol% benzoic acid additives),A set of 2,2'-dihydroxy-l,l'-dinap hthyl(BINOL)derivatives chiral amide catalysts were used t o promote the catalytic asymmetric Michael additionreaction of Pyrazolin-5-ones to ?-nitroalkenes.The products were exh ibited high catalytic(yield of 92%)and stereoselectivity(93% ee).Further more,the methodology was applied successfu lly to the synthesis of enantiomerically pure pyrazolin-5-o ne derivatives.