论文部分内容阅读
Catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides to electron-deficient alkenes has arguably been one of the most ideal synthetic strategies for the stereoselective construction of spirocyclic pyrrolidines with spiro quaternary stereogenic.Most dipolarophiles employed in these reactions are 2-oxoindolin-3-ylidene1,while α-alkylidene succinimides have rarely been explored,and enantioselective cycloaddition of α-alkylidene succinimides to generate structurally diverse spirocyclic pyrrolidines derivatives is still a challenge.We have recently developed DHIPOH/Cu(OAc)2 system2,which displayed excellent catalytic activity and stereoselectivity in asymmetric 1,3-dipolar cycloaddition of azomethine ylides with alkylidene malonates.In order to further expand the scope of our catalytic system,we set out to design novel chiral N,O-ligands.In this presentation,the first catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides to α-alkylidene succinimides catalyzed by novel chiral N,O-ligand/Cu(OAc)2 system is introduced,affording dispiropyrrolidine derivatives in good to high yields,excellent level of diastereoselectivities and enantioselectivities.