Three-component 1,3-dipolar cycloaddition reactions in synthesis of spiro[pyrrolidine-2,3 '-oxindoline] derivatives

Regio- and stereospecific syntheses of several spiro[pyrrolidine2,3'-oxindole] derivatives by cycloaddition trapping of azomethine ylides generated in situ, via decarboxylative condensation of isatin with alpha-amino acids or by reaction of secondary amines with isatin, are reported. 2,6-Dibenzylidenecyclohexanone, 2-arylidene-1-tetralone, and arylidenenzalononitrile derivatives have been efficiently used as trapping dipolarophiles. The regio- and stereochemistry of the additions are controlled by both frontier orbital and steric interactions. (C) 2002 Wiley Periodicals, Inc.