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

Abstract

Regio- and stereospecific syntheses of several spiro[pyrrolidine2,3′-oxindole] derivatives by cycloaddition trapping of azomethine ylides generated in situ, via decarboxylate condensation of isatin with α-amino acids or by reaction of secondary amines with isatin, are reported. 2,6-Dibenzylidenecyclohexanone, 2-arylidene-1-tetralone, and arylidenemalononitrile derivatives have been efficiently used as trapping dipolarophiles. The regio- and stereochemistry of the additions are controlled by both frontier orbital and steric interactions.