Catalytic asymmetric construction of spiro[pyrrolidine-2,3′-oxindole] scaffolds through chiral phosphoric acid-catalyzed 1,3-dipolar cycloaddition involving 3-amino oxindoles†
Abstract
The catalytic asymmetric three-component 1,3-dipolar cycloaddition of 3-amino oxindoles with aldehydes and nitroolefins under the catalysis of a chiral phosphoric acid is reported. The reaction provides a facile approach to synthesize a diverse array of spiro[pyrrolidine-2,3′-oxindoles] in high yields with excellent diastereo- and enantioselectivities under mild conditions.