Chen Gong He Gang team of Nankai University: efficient construction of new chiral IR (III) catalyst induced intramolecular hydrocarbon bond amination - γ - lactam

γ - lactam is a kind of very important compounds, which widely exists in drug molecules and natural products At present, there are many methods to prepare racemic γ - lactam, but its asymmetric synthesis still has some challenges Recently, Chen Gong and He Gang, the State Key Laboratory of elemental organic chemistry, Nankai University, based on the previous strategy of C-H bond activation assisted by bidentate guiding group, designed and synthesized a new type of chiral ligand (QAA ligands) containing 8-aminoquinoline group using amino acid as the parent structure, and prepared the corresponding chiral IR (III) catalyst Under the action of the catalyst, the C (SP 3) - H bond amination of dioxazolone compounds can be precisely controlled, and the efficient asymmetric synthesis of γ - lactam can be realized by more than 99% ee This kind of new catalyst has certain enzyme like properties and can tolerate the presence of a large amount of water, and the presence of water has a significant promotion effect on specific substrates Through the analysis of the single crystal structure of the catalyst, the author found that the pentamethylcyclopentadienyl (Cp *), 8-aminoquinoline (AQ) and o-phenylenedicarbonamide (nphth) in this kind of chiral IR (III) catalyst formed a regular channel like chiral cavity, and the metal center was in the interior of the hand cavity, so that it had excellent stereo control ability By cooperating with Professor sukbok Chang of Korea Institute of advanced technology in computational chemistry, it is found that the key factor of chirality control is the existence of multiple weak C-H / π interactions between the C-H bond and nphth group in the substrate Wang Hao, a postdoctoral researcher of the group, and Bai Ziqian, a master student, were the main participants in the work experiment Yoonsu Park, Ph.D., of Korea Institute of higher technology, provided theoretical calculation support for the research work The results were published in J am Chem SOC (J am Chem SOC., 2019, 141, 7194-7201).