Visible Light-Promoted Synthesis of Organic Carbamates from Carbon Dioxide under Catalyst- and Additive-Free Conditions

An efficient and environmentally friendly method for the synthesis of organic carbamates from carbon dioxide has been developed via photolysis of α-aryldiazoesters under mild conditions in the absence of any catalysts and additives. By using different solvent, a four- or three-component coupling reaction involving aryl diazoesters, amines and carbon dioxide could occur rapidly and selectively, giving a variety of structurally diverse organic carbamates in moderate to high yields.