Visible-Light-Driven One-Pot Synthesis of Polycyclic-Fused Amino-Thiazoles and Amino-Selenazoles via HFIP-Promoted Multicomponent Cyclizations

Herein, we report a multicomponent reaction (MCR) involving arylglyoxal, 4-hydroxycoumarin or 4-hydroxy-1-methyl-2(1H)-quinolone, and thiourea or selenourea in the presence of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and visible light to synthesize novel pentacyclic-fused aminothiazoles and amino-selenazoles. The reaction proceeds via a one-pot, two-step process: first, an HFIP-mediated three-component cyclization with the formation of two C-C bonds, one C-N bond, and one C-S/Se bond that yields trisubstituted aminothiazoles or amino-selenazoles, followed by a photocyclization step under white LED irradiation, which results in the formation of pentacyclic-fused thiazoles or selenazoles. The overall protocol follows green chemistry principles, offering an atom-economical, energy-efficient, and environmentally benign approach under mild reaction conditions and ambient temperature using visible light as a sustainable energy input.