Photo-induced generation of highly acidic species for the development of C-C bond-forming reaction

Research Project

Project/Area Number	18K19073
Research Category	Grant-in-Aid for Challenging Research (Exploratory)
Allocation Type	Multi-year Fund
Review Section	Medium-sized Section 33:Organic chemistry and related fields
Research Institution	Nagoya University
Principal Investigator	Ohmatsu Kohsuke 名古屋大学, 工学研究科(WPI), 特任准教授 (00508997)
Project Period (FY)	2018-06-29 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000) Fiscal Year 2019: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000) Fiscal Year 2018: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
Keywords	ラジカルイオン / 酸性度 / 光レドックス触媒 / ブレンステッド酸 / 不斉触媒反応 / 有機光化学
Outline of Final Research Achievements	We developed a strategy for the allylic C-H alkylation of enol silyl ethers and their derivatives, which relies heavily on the combined use of appropriate photoredox and Bronsted base catalysts for the generation of requisite allylic radicals while suppressing undesired desilylation process. Under the hybrid catalysis, a series of enol silyl ethers smoothly react with electron-deficient olefins to give the corresponding functionalized enol silyl ethers. This operationally simple protocol, in concert with the ready availability of enol silyl ethers and their conventional polar reactivity, provides rapid and reliable access to an array of complex carbonyl compounds and will find widespread use among practitioners of organic synthesis.
Academic Significance and Societal Importance of the Research Achievements	ラジカルカチオンの高い酸性度を改めて明示し、適切な触媒を用いることでメソリティック開裂によるフリーラジカルの生成過程を制御できることを実証した点で、有機化学分野に有益な知見を与えることができた。この知見をもとに様々な反応開発が可能になることから、萌芽的研究としての役割を十分に果たしたと考えられる。また、開発した反応は、従来変換困難であった位置での結合形成を可能にするため、天然物や医薬品などの複雑化合物の新規誘導体の提供につながると期待される。