Photoredox synthesis of functionalized quinazolinesviacopper-catalyzed aerobic oxidative Csp2-H annulation of amidines with terminal alkynes

Abstract

We have developed a visible light-induced photo-redox copper-catalyzed oxidative Csp2-H annulation (Friedel-Crafts-type cyclization) of amidines with terminal alkynes at room temperature to synthesize functionalized quinazolines. We report copper(i)-phenylacetylide catalyzed photo-oxidative Csp2-H annulation of amidines at RT, which is very challenging and complementary to the conventional transition metal-catalyzed thermal annulation reactions. We have demonstrated the application of this method by synthesizing anti-cancer compounds. Moreover, green chemistry metrics (theE-factor is ∼1.9 times better than that of the reported thermal method) and Eco-Scale (scales 55.4, which shows an acceptable synthesis) evaluations show that this method is eco-friendly and environmentally feasible.