Molecular Design of Transition Metal/Lewis Acid Combined Catalysts and Their Applications to Site-Selective Functionalization of Heterocycles

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K23375
• Research Category: Fund for the Promotion of Joint International Research (Home-Returning Researcher Development Research)
• Allocation Type: Multi-year Fund
• Review Section: Chemistry
• Research Institution: Tohoku University
• Principal Investigator: Yoshikai Naohiko 東北大学, 薬学研究科, 教授 (50401170)
• Co-Investigator(Kenkyū-buntansha): 砂田 祐輔 東京大学, 生産技術研究所, 教授 (70403988)
• Project Period (FY): 2021-03-12 – 2024-03-31
• Keywords: 有機合成 / 触媒 / 遷移金属 / ルイス酸 / 結合活性化

Outline of Final Research Achievements

This research project aimed at the precise molecular design of transition metal/main group Lewis acid combined catalysts for use in advanced molecular transformations involving the activation of inert chemical bonds. The major achievements of the project are as follows: 1) We successfully developed cobalt/aluminum and cobalt/magnesium catalysts supported by a phosphine/secondary phosphine oxide (PSPO) bifunctional ligand for the site-selective C-H alkenylation of pyridines, pyridones, and imidazopyridines with alkynes. A reaction mechanism involving a ligand-to-ligand hydrogen transfer process was revealed by density functional theory calculations. 2) We developed a cobalt/zinc catalytic system for the carbo- and hydrocyanation reactions of alkynes using organonitriles via carbon-cyano bond activation. Furthermore, depending on the presence or absence of the zinc catalyst, a switching of the stereochemistry of the C=C bond of the acrylonitrile derivatives was achieved.

Free Research Field

有機化学

Academic Significance and Societal Importance of the Research Achievements

単純で入手容易な有機分子の直接的かつ位置選択的な官能基化は，複雑分子の合成や医薬品のリード化合物探索を加速するうえで強力なアプローチである。本研究で見出した，遷移金属・ルイス酸複合触媒によるヘテロ環化合物や有機ニトリル化合物の結合活性化を伴う分子変換は，有機金属反応化学・触媒有機化学における重要な知見であるとともに，有用分子の迅速供給に資する新たな手法や設計指針を与えるものと期待される。