Sato Shunta, Sasaki Wataru, Sekino Tomoyuki, Yoshino Tatsuhiko, Kojima Masahiro, Matsunaga Shigeki
Faculty of Pharmaceutical Sciences.
Global Station for Biosurfaces and Drug Discovery, Hokkaido University.
Chem Pharm Bull (Tokyo). 2023;71(2):79-82. doi: 10.1248/cpb.c22-00520.
Metallaphotoredox-catalyzed allylation represents an emerging synthetic methodology that enables allylic substitution using nucleophilic radical species. The C-H allylation of N-aryl tetrahydroisoquinolines is an innovative example in this area and allows access to synthetically useful precursors for the further derivatization of tetrahydroisoquinolines. However, previous methods have required the use of noble metals, which has hampered their application due to concerns over their sustainability. Here we report the C-H allylation of N-aryl tetrahydroisoquinolines using a cobalt/organophotoredox dual catalyst system. Based on precedent, control experiments and controlled irradiation experiments, a mechanism for the cobalt/photoredox-catalyzed allylation that involves a π-allyl cobalt complex is proposed.
金属光氧化还原催化的烯丙基化反应是一种新兴的合成方法，它能够利用亲核自由基物种实现烯丙基取代反应。N-芳基四氢异喹啉的C-H烯丙基化反应是该领域的一个创新实例，可为四氢异喹啉的进一步衍生化提供具有合成价值的前体。然而，先前的方法需要使用贵金属，由于对其可持续性的担忧，这阻碍了它们的应用。在此，我们报道了使用钴/有机光氧化还原双催化剂体系实现N-芳基四氢异喹啉的C-H烯丙基化反应。基于先例、对照实验和可控辐照实验，提出了一种涉及π-烯丙基钴配合物的钴/光氧化还原催化烯丙基化反应机理。
