Synthesis of Aminated C-3 Aryloylated Benzofuran, Furopyridine, Benzothiophene, and Indole Derivatives from 1,6-Enyne and N-Aminopyridinium Salt in Visible Light

Abstract

We report a visible-light-assisted tandem oxidative 5-exo-dig cyclization of 1,6-enynes for the synthesis of aminated C-3 aryloylated benzofuran, furopyridine, benzothiophene, and indole derivatives. The nitrogen-centered radical generated in situ from N-aminopyridinium salt initiates the consecutive formation of C–N, C–C, and C–O bonds. The methodology exhibits good functional group tolerance and regioselectivity, furnishing products in good to excellent yields at room temperature. Preliminary biological screening of synthesized molecules reveals their potential as anticancer agents.