Asymmetric[3+2] Cycloaddition Catalyzed By Dinuclear Zinc Cooperative Catalyst To Synthesis Chiral Trifluoromethyl-substituted 2,3-Pyrrolidinyl Dispirooxindoles

Spirooxindole bone has been recognized as a key core in many natural products,synthetic compounds,and clinical pharmaceuticals.Especially,some chiral spirocyclic oxindoles containing a pyrrolidine framework have showed wide range of prominent bioactivitie such as anticancer,antifungal,antibacterial,and antimitotic activities.For example,horsfiline A,a new oxindole alkaloid containing a pyrrolidine spirooxindole framework,was isolated from Horsfieldia superba,which has been used as medicine.This thesis describes a new chiral dinuclear zinc cooperative catalytic asymmetric[3+2]cycloaddition of CF₃-containing N-unprotected isatin-derived azomethine ylides and methyleneindolinones,which is cooperatively catalyzed by Br?nsted base and Lewis acid.Under the optimal reaction condition?10 mol%of dinuclear zinc catalyst,4?MS as additive,in THF at 25°C?,a series of new trifluoromethyl-substituted 2,3-pyrrolidinyl dispirooxindoles with four continuous stereocenters,including two adjacent spiro-quaternary stereocenters are efficiently obtained in good yields?72-96%?with high diastereoselectivities?>20:1?and enantioselectivities?up to 99%?.Based on the absolute structure of product and literature reports,a possible mechanism of the reaction is proposed.