A highly efficient base-mediated diastereoselective [4 + 1] cycloaddition of ortho-tosylaminophenyl-substituted p-QMs with 3-chlorooxindoles has been developed to afford 3,2′-pyrrolidinyl spirooxindoles in high yields with high diastereoselectivity through a domino 1,6-addition/cyclization sequence. This reaction exhibits broad substrate scope and excellent functional group tolerance.