Catalytic Asymmetric Synthesis of Tetrahydrofuran Spirooxindoles via a Dinuclear Zinc Catalyst

An asymmetric Michael/hemiketalization and FridelCrafts reaction has been reported through a one-pot reaction. A number of structurally novel tetrahydrofuran spirooxindoles are synthesized in the presence of a 10 mol % dinuclear zinc catalyst with diastereomer ratios (dr) of 3:1–13:1 and an enantiomeric excess (ee) of 75–99%. The reaction can be performed on a gram scale without impacting its efficiency. The absolute configuration of products is confirmed by X-ray single crystal structure analysis, and a possible mechanism is proposed.