Copper-catalyzed tandem cyclization via (C–O) arylation and oxidative acylation for the construction of chromeno-fused isoxazole derivatives

Abstract

An effective intermolecular copper-catalyzed tandem reaction of 3-phenylisoxazol-5(4H)-one with ortho-halobenzaldehyde compounds yielded the corresponding chromeno-fused isoxazole derivatives in a straightforward manner; these derivatives are highly important in medicinal chemistry as potential bioactive building blocks. This unified approach features a simultaneous one-pot synthetic protocol for the construction of two new C–C and C–O bonds and a novel chromeno-fused isoxazole heterocycle in moderate to good yields. Notably, the designed methodology is sustainable and practicable because of the easy availability of its starting materials, environmental friendliness and a broad range of substrate scope, and it can be carried out using earth-abundant-metal-based catalysts like those of copper.