Catalytic asymmetric synthesis of 2,5-dihydrofurans using synergistic bifunctional Ag catalysis

Org Biomol Chem. 2019 Oct 14;17(38):8737-8744. doi: 10.1039/c9ob01903k. Epub 2019 Sep 25.

Abstract

We report a bifunctional Ag catalyst promoted intramolecular capture of oxonium ylides with alkynes for the enantioselective synthesis of 2,5-dihydrofurans. This represents unprecedented synergistic catalysis of a bifunctional Ag catalyst. Mechanistic studies revealed that [(R)-3,5-DM-BINAP](AgSbF6)2 (9) is likely to be the active catalytic species and that the reaction involves second order kinetics with respect to 9, suggesting that two molecules of 9 are involved in the intramolecular trapping of a Ag-associated oxonium ylide with a Ag-activated alkyne. Based on our mechanistic hypothesis, we further optimized the reaction, rendering a facile approach to 2,5-dihydrofurans in good to excellent yields in a highly chemo- and enantioselective fashion.

Publication types

  • Research Support, Non-U.S. Gov't