The Squaramide‐Catalyzed 1,3‐Dipolar Cycloaddition of Nitroalkenes with N‐2,2,2‐Trifluoroethylisatin Ketimines: An Approach for the Synthesis of 5′‐Trifluoromethyl‐spiro[pyrrolidin‐3,2′‐oxindoles]

Abstract A Cinchona alkaloid‐derived squaramide‐catalyzed asymmetric cycloaddition of trfluoromethyl‐containing azomethine ylides with β‐nitroalkenes was realized under mild conditions. A series of biologically important 5′‐trifluoromethyl‐ spiro[pyrrolidin‐3,2′‐oxindoles] was synthesized efficiently by this process in excellent yields, enantioseletivities and diastereoselectivities. magnified image