Catalytic asymmetric exo'-selective [3+2] cycloaddition for constructing stereochemically diversified spiro[pyrrolidin-3,3'-oxindole]s

Abstract

The first catalytic asymmetric exo'-selective [3+2] cycloaddition of methyleneindolinones with iminoesters was achieved for construction of novel diastereomers of spiro[pyrrolidin-3,3'-oxindole]. By using the imidazoline-aminophenol-ligand complex [Ni(OAc) 2-(L1)], the reaction proceeds in the stepwise Michael-Mannich reaction to give the exo' adducts as stable isomers (see scheme). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.