アリルC-H結合のPd (II) -触媒化されたリン酸化
Chen-Guo Feng1, Mengchun Ye, Kai-Jiong Xiao
1Department of Chemistry, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, United States.
Journal of the American Chemical Society
|June 13, 2013
まとめ
新しいパラジアム触媒反応により,ヘテロサイクルの直接的なC-Hリン酸化が可能になる. この方法は,H-フォスフォナートとディアリルフォスフィン酸化物を効率的に結合させ,多用途の合成経路を提供します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 有機金属化学 有機金属化学
- カタリシス カタリシス カタリシス
背景:
- C-H機能化は,現代の有機合成における重要な戦略である.
- パラジウム触媒は,C-H結合の活性化と変換のための強力なツールを提供します.
- 効率的なリン酸化方法の開発は,依然として重要な合成課題です.
研究 の 目的:
- 新しいパラジウム (((II) 触媒によるC-Hリン酸化反応を開発する.
- 地域選択的機能化のために,ヘテロサイクルの指向のオルトパラデーションを活用する.
- この変革のためのコップリング・パートナーの範囲を探求する.
主な方法:
- C-H活性化のためのパラジウム (II) 触媒を使用する.
- オーソパラダーションの指導グループによる支援を活用する.
- 結合パートナーとしてH-フォスフォナートとダイアリルフォスフィン酸化物との反応を調査する.
主要な成果:
- ヘテロサイクルのPd (((II)) 触媒化されたC-Hリン酸化を成功裏に開発しました.
- ヘテロサイクルの誘導によるオーソパラデーションの有用性を実証した.
- H-フォスフォナートとダイアリルフォスフィン酸化物の両方が効果的な結合パートナーであることを確認しました.
結論:
- 開発された方法は,C-H酸化のための効率的な経路を提供します.
- この反応は,C-H機能化におけるパラジウム触媒の汎用性を示しています.
- このアプローチは,リン酸化ヘテロサイクルの合成のためのツールキットを拡張します.
関連する概念動画
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para position.
Cationic Chain-Growth Polymerization: Mechanism
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Nucleophilic Aromatic Substitution: Elimination–Addition
Simple aryl halides do not react with nucleophiles. However, nucleophilic aromatic substitutions can be forced under certain conditions, such as high temperatures or strong bases. The mechanism of substitution under such conditions involves the highly unstable and reactive benzyne intermediate. Benzyne contains equivalent carbon centers at both ends of the triple bond, each of which is equally susceptible to nucleophilic attack. This 50–50 distribution of products is confirmed through isotopic...
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
![[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
![Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F51444.jpg&w=3840&q=50)