Direct Catalytic Asymmetric Vinylogous Mannich-Type Reaction of γ-Butenolides with Ketimines

Authors


  • This work was financially supported by JSPS KAKENHI (Grant Number 25713002) and JST, ACT-C. L.Y. thanks JSPS for a postdoctoral fellowship. Akinobu Matsuzawa is gratefully acknowledged for technical assistance in X-ray crystallographic analysis of 3 a. We thank Dr. Youmei Bao for technical support in spectral data collection.

Abstract

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A cooperative catalyst consisting of a soft Lewis acid and a hard Brønsted base promoted the title reaction. The N-thiophosphinoyl group on the ketimines was critical to surpass the high activation barrier through the soft–soft interaction of sulfur and copper. Mannich adducts with a tetrasubstituted stereogenic center were produced with excellent diastereo- and enantioselectivities. TANIAPHOS= ferrocenyl ligand.

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