N-Heterocyclic Carbene-Catalyzed 1,6-Addition of Homoenolate Equivalent Intermediates: Asymmetric Synthesis of Nonspirocyclic Quaternary Oxindoles

Although there is a growing interest in developing asymmetric 1,6-addition reactions of carbon nucleophiles to Michael acceptors, the corresponding 1,6-addition of homoenolates remains an unsolved ...