CuO nanoparticles and nanobelts catalyzed potent synthesis of benzopyran derivatives

CuO nanobelts and nanoparticles were selectively synthesized using specific precipitating agents such as NaOH and Na 2 CO 3 , respectively. Catalytic activity of these nanocrystals is explored by synthesizing a series of benzopyran derivatives by reaction of dimedone, aryl aldehydes and malononitrile in a water:ethanol (70:30) mixture. The developed protocol is endowed with appealing features such as a recyclable catalyst, high yields and shorter reaction time. Graphic abstract