Organocatalytic Asymmetric [3 + 2] Cycloaddition of N-2,2,2-Trifluoroethylisatin Ketimines with β-Trifluoromethyl Electron-Deficient Alkenes: Access to Vicinally Bis(trifluoromethyl)-Substituted 3,2′-Pyrrolidinyl Spirooxindoles

• DOI: 10.1021/acs.orglett.8b01730
• Publication Date: 2018-07-25T18:35:21Z
• Authors: Yong You; Wen-Ya Lu; Zhen-Hua Wang; Yong-Zheng Chen; Xiao-Ying Xu; Xiao-Mei Zhang; Wei-Cheng Yuan
• Keywords: 01 natural sciences; 0104 chemical sciences

N-2,2,2-Trifluoroethylisatin ketimines with β-trifluoromethyl enones, 3-trifluoroethylidene oxindole, and benzofuranone can undergo asymmetric [3 + 2] cycloaddition, catalyzed by chiral bifunctional squaramide-tertiary amine catalysts, affording a wide spectrum of 3,2'-pyrrolidinyl spirooxindoles. The significance this protocol is highlighted its extremely high efficiency in the construction structurally diverse spirocyclic oxindoles, bearing vicinally bis(trifluoromethyl)-substituted pyrrolidine moiety, including four contiguous stereocenters, yields excellent stereocontrol.