Controlled partial transfer hydrogenation of quinolines by cobalt-amido cooperative catalysis

• Published in: Nature communications Vol. 11; no. 1; pp. 1249 - 9
• Main Authors: Pang, Maofu, Chen, Jia-Yi, Zhang, Shengjie, Liao, Rong-Zhen, Tung, Chen-Ho, Wang, Wenguang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06.03.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/131; 140/58; 639/638/549/933; 639/638/77/885; 639/638/77/888; Catalysis; Catalysts; Cobalt; Functional groups; Humanities and Social Sciences; Hydrogenation; multidisciplinary; Organic compounds; Quinoline; Quinolines; Reduction; Regioselectivity; Room temperature; Science; Science (multidisciplinary); Substrates
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-15118-x

Catalytic hydrogenation or transfer hydrogenation of quinolines was thought to be a direct strategy to access dihydroquinolines. However, the challenge is to control the chemoselectivity and regioselectivity. Here we report an efficient partial transfer hydrogenation system operated by a cobalt-amido cooperative catalyst, which converts quinolines to 1,2-dihydroquinolines by the reaction with H 3 N·BH 3 at room temperature. This methodology enables the large scale synthesis of many 1,2-dihydroquinolines with a broad range of functional groups. Mechanistic studies demonstrate that the reduction of quinoline is controlled precisely by cobalt-amido cooperation to operate dihydrogen transfer from H 3 N·BH 3 to the N=C bond of the substrates. Controlling the partial reduction of quinolines is challenging, given the competing overreduction to tetrahydroquinolines. Here, the authors report a cobalt-amido cooperative catalyst for the selective, partial transfer hydrogenation of quinolines to 1,2-dihydroquinolines with H 3 N·BH 3 as reductant.