An efficient synthesis of 2H-chromen-3-yl derivatives via CuI/(NH4)2HPO4 catalyzed reaction of O-propargyl salicylaldehydes with active methylene compounds

2H-Chromen-3-yl-methylenemalononitriles/cyanoacrylates/cyanoacrylamides with variant structural features have been serendipitously formed during an endeavour to prepare 5H-chromeno[3,4-c]pyridine using CuI/(NH4)2HPO4 catalyzed reaction of O-propargyl salicylaldehyde with malononitrile/ethyl cyanoacetate/cyanoacrylamide. The process is convenient, speedy and high yielding, and the products formed have been finally characterized by X-ray diffraction analysis.