Enantioselective Insertion of Metal Carbenes into NH Bonds: A Potentially Versatile Route to Chiral Amine Derivatives

Back to copper: The Rh-catalyzed reactions of diazocarbonyl compounds with amines, leading to NH insertion products, have found wide application. However, an enantioselective variant has remained elusive. A return to copper catalysis, first reported for carbene NH insertions over 50 years ago, in the presence of chiral ligands and a large noncoordinating counterion, has resulted in enantioselective NH insertion into anilines.