Direct Photoexcitation of Benzothiazolines: Acyl Radical Generation and Application to Access Heterocycles

Molecules. 2021 Nov 12;26(22):6843. doi: 10.3390/molecules26226843.


An acyl radical generation and functionalization strategy through direct photoexcitation of benzothiazolines has been developed. The formed acyl radical species can either be trapped by quinoxalin-2-ones to realize their C(3)-H functionalization or trigger a cascade radical cyclization with isonitriles to synthesise biologically important phenanthridines. The synthetic value of this protocol can be further illustrated by the modification of quinoxalin-2-ones, containing important natural products and drug-based complex molecules.

Keywords: benzothiazolines; heterocycles; photochemistry.