Synthesis and evaluation of properties of imidazo[1,5-a]pyridine carbenes

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05769
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Synthetic chemistry
• Research Institution: Gifu University
• Principal Investigator: Shibahara Fumitoshi 岐阜大学, 工学部, 准教授 (60362175)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 含窒素複素環カルベン / 遷移金属触媒

Outline of Final Research Achievements

Previously, we estimated that imidazo[1,5-a]pyridine derived carbenes have different electronic character from the conventional carbenes, thus those compounds were actually synthesized and evaluated those properties. The synthesis were carried out with our previously developed methods and a variety of compounds were obtained. The compounds readily derived to the corresponding Rh-CO complexes, and we measured several spectra of the complexes and estimated their donor and accepter characters by DFT calculations. As a result, we revealed that the carbenes indicated meaningful pi-accepting character. With this feature, we also assayed catalytic activities for several reactions and found that the catalyst having the ligands showed good catalytic activity when the reaction includes migratory insertion, and beta-elimination that usually well induced by pi-acidic metals.

Free Research Field

有機合成化学

Academic Significance and Societal Importance of the Research Achievements

これまで含窒素複素環カルベンは、アクセプター性はほとんど無いとされていて、実際にそれの性質を利用した錯体触媒開発が進められてきた。しかし、アクセプター性を持つ同様の化学種の提供は、新しい触媒活性を持つ化学種を創出することにつながり、新しい触媒反応を展開することが可能になる。今回われわれは、実際にそのような性質を持つ含窒素カルベンの創出に成功し、それらが確かに、これまで使われてきた含窒素複素環カルベン配位子を持つ金属錯体とは異なる反応性を示すことを証明したため、今後、その性質を利用した新たな触媒反応開発の展開が見込まれる。