Creation of Highly Electrophilic Divalent Silicon Scpecies for Small Molecules Activation

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22188
• 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: University of Tsukuba (2020); Nagoya City University (2019)
• Principal Investigator: Sasamori Takahiro 筑波大学, 数理物質系, 教授 (70362390)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 元素資源 / フェロセン / シリレン / ケイ素 / 求電子性 / 酸化還元 / 小分子変換

Outline of Final Research Achievements

The final goal of this research project is the creation of a super-electrophilic silylene, which is a divalent silicon species with extremely high electrophilicity due to its vacant p-orbital and cationic charge. It can be expected the introduction of ferrocenly groups towards the silylene moiety could afford the Redox-controlable electrophilicity depending on the electrochemical properties of the ferrocenyl moieties.
During the course of this project, we have succeeded in the synthesis of a sterically demanding bis(ferrocenyl)dichlorosilane, which would be kinetically protected in order to exist as a monomeric silylene. The reduction of the dichlorosilane with sodium afforded the corresponding silirane derivative, having Si-C-C three-membered ring skeleton. It was found that the obtained silirane could work as a suitable precursor of the corresponding bis(ferrocenyl)silylene under mild conditions.

Free Research Field

有機元素化学

Academic Significance and Societal Importance of the Research Achievements

窒素や二酸化炭素など豊富な資源を変換するための小分子変換触媒開発は世界的な重要課題である。加えて、稀少元素に替えて豊富な元素を活用する元素資源問題も重要視されている。開発に成功した、鉄とケイ素からなるビス（フェロセニル）シリレンは、豊富元素による小分子変換触媒として期待できる新物質である。今後、本研究成果を基盤として、電気化学的な酸化還元によりこのシリレンの反応性を制御し、超求電子性シリレンへと展開できれば、資源問題に対する解決の糸口となり得る。「シリレンの酸化還元による反応性制御」という反応設計は一般性の高い反応原理となり、これが確立すれば様々な分子変換反応に適用でき、波及効果は大きい。