| 研究課題/領域番号 |
16J11354
|
|---|
| 研究機関 | 京都大学 |
|---|
研究代表者 |
ZHAO QIANG 京都大学, 工学研究科, 特別研究員(DC1)
|
|---|
| 研究期間 (年度) |
2016-04-22 – 2019-03-31
|
| キーワード | carbene / C-H functionalization / rhodium / triazole / alkyne |
|---|
| 研究実績の概要 |
We studied on a rhodium(II)-catalyzed reaction of N-sulfonyl-1,2,3-triazoles with 2-alkenols. The reaction is initiated by insertion of an α-imino carbene into the O-H linkage of alcohol, forming a 2-alkenoxy enamide intermediate. A thermal [3,3]-sigmatropic rearrangement follows to yield 2-substituted 2-amino ketone in a stereoselective manner. Finally, a successful application of this methodology to a formal synthesis of (-)-α-conhydrine was also studied.
We also developed a new kind of triazoles. We found that it could generate acceptor-acceptor rhodium carbene complex in the presence of rhodium catalyst. The in-situ generated acceptor-acceptor rhodium carbene complex could react with simple arenes, leading to the formation of enaminones via aromatic C-H functionalization.
|
| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
Reactions of carbenes substituted by two acceptor groups generated from 1,2,3-triazoles are yet to be reported. Here we found a rhodium(II)-catalyzed reaction of simple arenes with 4-acyl-1-mesyl-1,2,3-triazoles. Enaminones are synthesized via aromatic C-H functionalization with carbene species substituted with two acceptor groups. Interestingly, the reaction takes place exclusively at the aromatic C(sp2)-H bonds in the presence of benzylic C(sp3)-H bonds. Preliminary mechanistic study indicates an electrophilic aromatic substitution pathway via a zwitterionic intermediate rather than a concerted C-H insertion pathway.
|
| 今後の研究の推進方策 |
In the following year, we are going to develop new reactions using our new developed 4-Acyl-1-mesyl-1,2,3-triazoles. As our new developed triazoles are classified as acceptor-acceptor carbenes which are different from previous reported triazoles. We hope, we can develop unique new reactions using our new triazoles which cannot do using previous reported triazoles.
|
