Development of catalytic radical reactions by controlling oxidative and reductive processes

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K06954
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 47010:Pharmaceutical chemistry and drug development sciences-related
• Research Institution: Hyogo Medical University (2022-2023); Hyogo University of Health Sciences (2020-2021)
• Principal Investigator: Miyabe Hideto 兵庫医科大学, 薬学部, 教授 (10289035)
• Co-Investigator(Kenkyū-buntansha): 甲谷 繁 兵庫医療大学, 薬学部, 教授 (00242529)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 有機合成 / ラジカル / 有機触媒 / 光触媒 / 鉄触媒 / 酸化 / 還元

Outline of Final Research Achievements

The catalytic radical reactions were developed by using photocatalysts and Fe-catalysts. These catalysts have the potential to induce the oxidative and reductive radical processes. (1) The oxidative transformation of α,β-unsaturated ketones was achieved under the conditions using rhodamine 6G as a photocatalyst and BrCCl3 as a mild co-oxidant. This oxidative transformation is promoted by the bromine atom-transfer to intermediate radicals from BrCCl3. (2) The oxidative esterification of aldehydes was achieved under the organocatalytic conditions based on the cooperation between N-heterocyclic carbene (NHC) and eosin Y. In this reaction, the oxidation of Breslow intermediates is promoted by the activated photocatalyst and C2Cl6. (3) FeCl3-promoted oxidative radical cyclization of active methylenes was developed. The reaction of α-chloro-active methylenes proceeded by using the sub-catalytic amount of FeCl2.

Free Research Field

有機合成化学

Academic Significance and Societal Importance of the Research Achievements

従来のラジカル発生法は、還元的方法と酸化的方法に二分でき、いずれも化学量論量以上の試薬を用いる場合が多く、ラジカル発生に過剰の試薬を必要とする点では環境への負荷が大きい。ラジカル合成化学を環境調和型反応に発展させるためには、ラジカル反応の触媒化が不可欠である。本研究は、光触媒や鉄触媒を活用した酸化的ラジカル反応の触媒化を研究し、有機化学分野や触媒化学分野の発展に貢献する。