Synthesis and Application of New Triplet and Singlet Carbenes

2016 Fiscal Year Final Research Report

• Project/Area Number: 26288017
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Organic chemistry
• Research Institution: Hiroshima University
• Principal Investigator: Yamamoto Yohsuke 広島大学, 理学(系)研究科(研究院), 教授 (50158317)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: カルベン / 合成 / 構造 / 反応中間体 / ESR

Outline of Final Research Achievements

Triplet carbenes are very difficult to stabilize, and the synthesis of isolable triplet carbenes is a worthwhile challenge. Tomioka et al. have reported two long-living carbenes in solution. However, the isolation of triplet carbenes in the solid state still remains to be achieved.
Recently, we proposed a new strategy for the generation of triplet carbenes by two-electron oxidation of allenic precursors bearing two thioxanthene or acridene moieties. Oxidation of allenic compound bearing two diphenoxyacridene moieties resulted in a cyclized product and 3,5-ditBuphenoexy substituted system resulted in a stable singlet carbene after two electron oxidation. But we succeeded in preparation of sterically very rigid allene and the oxidation afforded the target triplet carbene. Although the triplet carbene was stable only at low temperatures, we could observe the characteristic ESR signals of the target triplet carbene.

Free Research Field

有機化学