Assembly of spirooxindole derivatives containing four consecutive stereocenters by using cascade reactions catalyzed by an N-heterocyclic carbene

Abstract

In-spiro-ational: Biologically important and synthetically challenging spirocyclopentaneoxindoles with four consecutive stereocenters, including one spiroquaternary stereocenter, have been constructed in good yields and diastereoselectivity by a cascade reaction catalyzed by an N-heterocyclic carbene (see scheme). This reaction also provides a new strategy to access highly unusual tricyclic oxindoles.