Direct N-H/α,α,β,β-C(sp3)-H functionalization of piperidine via an azomethine ylide route: synthesis of spirooxindoles bearing 3-substituted oxindoles.

Direct N-H/α,α,β,β-C(sp3)-H functionalization of piperidine via an azomethine ylide route: synthesis of spirooxindoles bearing 3-substituted oxindoles.