从酒精和胺基合成胺基,通过挤出二
Lars Ulrik Nordstrøm1, Henning Vogt, Robert Madsen
1Center for Sustainable and Green Chemistry, Department of Chemistry, Building 201, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
Journal of the American Chemical Society
|December 9, 2008
概括
一种新的催化剂通过将酒精和氨基合在一起,释放二,使直接的胺合成成为可能. 这种绿色化学方法提供了从初级基质中获得二次胺的良好产量.
科学领域:
- 绿色化学和催化剂的应用
- 有机合成 有机合成
- 有机金属化学 有机金属化学
背景情况:
- 胺基合成在药品和材料中至关重要.
- 传统方法通常涉及苛刻的试剂或多个步骤.
- 开发可持续的催化路线是一个持续的挑战.
研究的目的:
- 介绍直接胺合成的环保方法.
- 为了利用一个简单的催化剂进行酒精-氨基合.
- 探索这种新胺形成的催化循环.
主要方法:
- 在现场生成一个活性催化剂从一个复合物,N-异环碳酸,和.
- 初级醇和初级胺之间直接合反应.
- 反应产品和中间体的表征.
主要成果:
- 从初级酒精和初级基胺中成功合成二次胺,产量很好.
- 释放两个二分子作为主要的副产品.
- 拟议的催化循环涉及中间体化物和与催化剂协调的 Hemiaminal.
结论:
- 已经开发出一种可持续和高效的胺合成催化系统.
- 该方法为传统的胺形成技术提供了一个更绿色的替代方案.
- 机械学的见解为进一步的催化剂优化提供了基础.
相关概念视频
Preparation of 1° Amines: Gabriel Synthesis
Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Carboxylic Acids to Methylesters: Alkylation using Diazomethane
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.
Preparation of Amides
Amides are synthesized by treating carboxylic acids with amines in the presence of dehydrating agents like dicyclohexylcarbodiimide (DCC).
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
Ethers from Alcohols: Alcohol Dehydration and Williamson Ether Synthesis
Overview
Ethers can be prepared from organic compounds by various methods. Some of them are discussed below,
Preparation of Ethers by Alcohol Dehydration
In this method, in the presence of protic acids, alcohol dehydrates to produce alkenes and ethers under different conditions. For example, in the presence of sulphuric acid, dehydration of ethanol at 413 K yields ethoxyethane, whereas it yields ethene at 443 K.
Ethers can be prepared from organic compounds by various methods. Some of them are discussed below,
Preparation of Ethers by Alcohol Dehydration
In this method, in the presence of protic acids, alcohol dehydrates to produce alkenes and ethers under different conditions. For example, in the presence of sulphuric acid, dehydration of ethanol at 413 K yields ethoxyethane, whereas it yields ethene at 443 K.
Aldehydes and Ketones with Amines: Enamine Formation Mechanism
Enamine formation involves the addition of carbonyl compounds to a secondary amine through a series of reactions. The mechanism begins with the generation of carbinolamine, a nucleophilic attack followed by several proton transfer reactions. The hydroxyl group of the carbinolamine is converted into water to make a better leaving group that can push the reaction forward by eliminating a water molecule. In enamine formation, the last step involves the abstraction of a proton from the α carbon to...
Preparation of Amines: Alkylation of Ammonia and Amines
Alkylation is one of the methods used to prepare amines. Direct alkylation of ammonia or a primary amine with an alkyl halide gives polyalkylated amines along with a quaternary ammonium salt through successive SN2 reactions. This process of making the quaternary salt through the direct alkylation method is called exhaustive alkylation.
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...


