Zn-ProPhenol Catalyzed Enantioselective Mannich Reaction of 2 H-Azirines with Alkynyl Ketones

Org Lett. 2020 Dec 18;22(24):9683-9687. doi: 10.1021/acs.orglett.0c03737. Epub 2020 Dec 3.

Abstract

The enantioselective Mannich reaction of 2H-azirines with alkynyl ketones is achieved under Zn-ProPhenol catalysis, delivering various aziridines with vicinal tetrasubstituted stereocenters in high yields with excellent enantioselectivities. The bimetallic Zn-ProPhenol complexes activate both the nucleophile and the electrophile in the same chiral pocket. A unique intramolecular hydrogen bond is observed in the obtained Mannich adducts, which lowers the basicity of the product's aziridine nitrogen thus favoring enantioselective control and allowing catalyst turnover.

Publication types

  • Research Support, Non-U.S. Gov't