Mg(ClO4)2-promoted [4 + 3] cycloaddition of oxindole derivatives with conjugated dienes: concise synthesis of spirocycloheptane oxindole derivatives

Abstract

We herein reported a novel Mg(ClO₄)₂-promoted intermolecular [4 + 3] cycloaddition reaction of oxindole derivatives and cyclopentadiene. This new strategy provides a convenient approach to the concise synthesis of a series of spirocycloheptane oxindole derivatives, with moderate to good yields and high diastereoselectivities.