窒素の還元により,より安全なアリルジアゾニウム化学を可能にします
Javier Mateos1, Tim Schulte1,2, Deepak Behera1,2
1Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim an der Ruhr, Germany.
Science (New York, N.Y.)
|April 25, 2024
まとめ
この研究は,危険な蓄積を回避する窒素還元を用いて,アリルジアゾニウム塩の合成のためのより安全な方法を導入しています. この新しいアプローチにより,アニリンから効率的な単段階のデアミナティブハロゲン化が可能になります.
科学分野:
- 有機化学
- 合成化学
背景:
- アリルジアゾニウム塩は有機合成において極めて重要であり,伝統的な製法方法は19世紀まで遡る.
- 他のアリルハリドよりも多くの場合,その反応性は,ダイアゾニウム化学の継続的な成長を促します.
- しかし,窒素ガスの容易な放出は,重大な安全リスクをもたらし,過去および現在進行中の事故につながります.
研究 の 目的:
- アリルディアゾニウム化学の 新しく安全なパラダイムを開発する
- ディアゾニウム塩の蓄積に伴うリスクを軽減するために
- ハロゲン化反応の効率を高めるため
主な方法:
- 電子ドナーとしてチオスルファートまたはジハロキュプラートを使用した窒素還元を含む新しいプロトコル.
- アリルディアゾニウムを短時間の中間物質として生成するために,速度制限の窒素還元ステップを使用する.
- アニリンから直接単一のステップでデアミナティブハロゲン化を行う.
主要な成果:
- 危険なアリルジアゾニウムの中間物質の蓄積を回避しました.
- 従来の方法と比較してより安全な反応条件を達成した.
- アニリンの効率的な,単段階のデアミナティブハロゲン化が実証されている.
- 亜酸化窒素の減少は,中間生成を制御する速度制限のステップとして識別された.
結論:
- 開発された方法は,安全を優先するダイアゾニウム化学における重要なパラダイムシフトを表しています.
- このアプローチは,アニリンからアリルハリドを合成するためのより安全でしばしばより効率的な代替手段を提供します.
- アリルジアゾニウムの一時的な生成は,爆発性蓄積のリスクを効果的に回避します.
関連する概念動画
01:371° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
3.8K
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
3.8K
01:19Diazonium Group Substitution: –OH and –H
2.8K
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
2.8K
01:14Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
2.1K
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,...
2.1K
01:261° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
3.3K
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...
3.3K
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
1.9K
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...
1.9K
01:13Preparation of Amines: Reduction of Amides and Nitriles
2.4K
Nitriles can be reduced to primary amines using reducing agents like lithium aluminum hydride or catalytic hydrogenation. The reduction introduces an amino group with an extra carbon in the skeleton. Nitriles are formed from the reaction between alkyl halides and sodium cyanide through the SN2 mechanism. Primary alkyl halides are the preferred substrates to prepare nitriles.
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...
2.4K