ChemInform Abstract: Copper‐Catalyzed Intramolecular C(sp3)—H and C(sp2)—H Amidation by Oxidative Cyclization.

• DOI: 10.1002/chin.201436113
• Publication Date: 2014-08-21T23:56:11Z
• Authors: Zhen Wang; Jizhi Ni; Yoichiro Kuninobu; Motomu Kanai
• Keywords: 01 natural sciences; 6. Clean water; 0104 chemical sciences

AbstractThe first copper‐catalyzed intramolecular C(sp3)H and C(sp2)H oxidative amidation has been developed. Using a Cu(OAc)2 catalyst and an Ag2CO3 oxidant in dichloroethane solvent, C(sp3)H amidation proceeded at a terminal methyl group, as well as at the internal benzylic position of an alkyl chain. This reaction has a broad substrate scope, and various β‐lactams were obtained in excellent yield, even on gram scale. Use of CuCl2 and Ag2CO3 under an O2 atmosphere in dimethyl sulfoxide, however, leads to 2‐indolinone selectively by C(sp2)H amidation. Kinetic isotope effect (KIE) studies indicated that CH bond activation is the rate‐determining step. The 5‐methoxyquinolyl directing group could be removed by oxidation.