Organocatalytic Visible Light Enabled SNAr of Heterocyclic Thiols: A Metal-Free Approach to 2-Aminobenzoxazoles and 4-Aminoquinazolines

J Org Chem. 2017 Dec 15;82(24):13256-13262. doi: 10.1021/acs.joc.7b02357. Epub 2017 Nov 28.

Abstract

The direct amination reaction of heterocyclic thiols has been developed in the presence of the nonhazardous photocatalyst Rose Bengal under irradiation of visible light. The reaction provides a straightforward approach to pharmaceutically and synthetically useful 2-aminobenzoxazole and 4-aminoquinazoline derivatives from the corresponding heterocyclic thiols with amines in good to excellent yields. Our photochemical reaction can be successfully adapted into a continuous flow reactor which is applicable for large-scale chemical industry. The key benefits of this reaction include the use of metal-free, low-cost Rose Bengal catalyst and practical operation (ambient temperature, open flask, and undried solvents).

Publication types

  • Research Support, Non-U.S. Gov't