アルファ・ボリル・ディアゾ化合物の多用途反応化学
Yao Liu1, Raimon Puig de la Bellacasa2, Bo Li1
1Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467-3860, United States.
Journal of the American Chemical Society
|August 25, 2021
まとめ
研究者は安定したα-ボリルダイアゾ化合物であるダイアゾメチル-1,2-アザボリンを開発した (1). この汎用的な構成要素は,C-HとO-H活性化を含む多様な合成有機反応を可能にし,ヘテロサイクルの化学を拡張します.
科学分野:
- 合成有機化学
- ヘテロサイクル化学
- オーガノボロン化学
背景:
- ダイアゾ化合物は有機合成において極めて重要であるが,安定性が欠けていることが多い.
- 新しく安定したダイアゾリアジントの開発は,合成方法の拡大に不可欠です.
- 1,2-アザボリンモチーフは,潜在的な応用を持つ重要なヘテロサイクル構造です.
研究 の 目的:
- 最初のα-ボリルディアゾ化合物を合成し,特徴づけること.
- この新しいダイアゾ化合物の反応性と合成有用性を調査する.
- 1,2-アザボリン合成のための汎用的な構成要素としての可能性を確立する.
主な方法:
- ディアゾメチル-1,2-アザボリン合成 (1).
- C-H活性化,O-H活性化,サイクル添加,ハロゲン化,ルテニウム触媒によるカルボニルオレフィネーションを含む反応化学の探索.
- フェニルジアゾメタンとの安定性と反応性の比較
主要な成果:
- 最初のα-ボリルダイアゾ化合物,ダイアゾメチル-1,2-アザボリンを成功して合成した (1).
- 化合物1はフェニルジアゾメタンと比較して安定性が著しく向上した.
- C-H/O-H活性化およびサイクル添加を含む様々なクラシックなダイアゾ反応タイプで広範な反応性を示した.
- ルテニウム触媒によるカルボニルオレフィネーションの有用性を示した.
結論:
- ディアゾメチル-1,2-アザボリン (1) は,安定し,多用途の合成構成要素である.
- その多様な反応性プロファイルは1,2-アザボリンヘテロサイクルの構築のための新しい道を開く.
- この発見は,新しいヘテロサイクルの化合物を探求する有機化学者に貴重なツールを提供します.
関連する概念動画
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
3.2K
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...
3.2K
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
2.3K
Treating arylamines with nitrous acid gives aryldiazonium salts that are effective substrates in nucleophilic aromatic substitution reactions. The diazonio group in these salts can be easily displaced by different nucleophiles, yielding a wide variety of substituted benzenes. The leaving group departs as nitrogen gas, and this easy elimination is the driving force for the substitution reaction.
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
2.3K
α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
3.3K
The method to achieve α-brominated carboxylic acids using a mixture of phosphorus tribromide and bromine is known as the Hell–Volhard–Zelinski reaction. The reaction is catalyzed by phosphorus tribromide, which can be used directly or produced in situ from red phosphorus and bromine. The mechanism comprises PBr3 catalyzed conversion of acid to acid bromide and hydrogen bromide. The acid bromide enolizes to its enol form in the presence of HBr. The nucleophilic enol attacks the...
3.3K
Carboxylic Acids to Methylesters: Alkylation using Diazomethane
2.5K
Carboxylic acids react with diazomethane in an ether solvent via alkylation at the carboxylate oxygen atom to give methyl esters of the corresponding acid with excellent yields.
2.5K
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.1K
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
2.1K
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
11.0K
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.
11.0K


