Synthesis of Aminobenzoic Acid Derivatives via Chemoselective Carbene Insertion into the −NH Bond Catalyzed by Cu(I) Complex

Phosphine
ligand stabilized air-stable Cu­(I) complexes have been
successfully used to functionalize the aromatic aminobenzoic acids
in a chemoselective manner without implementing protection and deprotection
strategy under mild reaction conditions. This chemoselective carbene
insertion into −NH bond over −COOH and −OH bonds
leads to the wide range of carboxy and hydroxy functionalized α-amino
esters (27 examples). All of the isolated new products have been fully
characterized using standard analytical methods.