Preparation of cyclophanes driven by pi-coordination of arenes to a transition-metal center

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K19080
• 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: The University of Tokushima
• Principal Investigator: OGASAWARA Masamichi 徳島大学, 大学院社会産業理工学研究部(理工学域), 教授 (70301231)
• Project Period (FY): 2018-06-29 – 2020-03-31
• Keywords: シクロファン / メタセシス / クロム / 鉄 / パイ配位 / ルテニウム / モリブデン

Outline of Final Research Achievements

In this research, a novel method of preparing cyclophanes was examined. Our idea was the use of transition-metals as templates to assemble two alkenylarenes by the pi-coordination to the metal. Subsequent olefin metathesis between the two ligating arene moieties and removal of the metal template might afford the corresponding cyclophane derivatives. During the course of our investigations, it was found that the bis(alkenylarene)chromium species was difficult to synthesize. Then, we turned our attention to the metathesis dimerization of (alkenylarene)chromium tricarbonyl species, which afforded the expected dimerized products in high yields in the presence of the Grubbs-II catalyst. The metathesis reaction of 1-butenyl-1'-vinylferrocene proceeded in the two different manners; one was the ring-closing metathesis giving the ferrocenophane, the other was the dimerization at the vinyl terminal, and the two reaction paths could be controlled by the proper choices of the conditions.

Free Research Field

有機金属化学

Academic Significance and Societal Importance of the Research Achievements

様々な機能を有する複雑な化合物を選択的に合成する手法は、有機合成における重要な技術である。なかでも、新たな「立体選択的合成手法」の開発は、活発な研究分野である。本研究では、「遷移金属触媒」を用いて「遷移金属化合物」を立体選択的に分子変換する新たな手法について検討した。遷移金属を含む化合物では、d軌道が結合に関与するため、古典的な有機化合物ではありえない特徴的な立体構造を示すものがある。本研究で対象としたのは、そのなかでも「面不斉」と呼ばれる立体現象の制御である。