Synthesis of fused oxazole-containing coumarin derivatives via oxidative cross coupling reaction using a combination of CuCl2 and TBHP

Abstract

Various fused oxazoles containing coumarin derivatives were synthesized via an oxidative cross coupling reaction by employing 20 mol% CuCl₂ as the catalyst and TBHP as an oxidant. The reaction proceeds through functionalization of a C–H bond by a cross-dehydrogenative coupling (CDC) pathway to produce various oxazole derivatives. The reaction protocol gives easy access to a number of oxazole derivatives containing the coumarin moiety at room temperature from various 3-(benzylamino)-2H-chromen-2-one derivatives.