通过第二代格鲁布斯催化剂进行酸盐转化:通过PCy3生成的酸盐启用了意想不到的途径
Gwendolyn A Bailey1, Deryn E Fogg1
1Center for Catalysis Research and Innovation and Department of Chemistry, University of Ottawa, Ottawa, Ontario K1N6N5 Canada.
Journal of the American Chemical Society
|June 2, 2015
概括
格鲁布斯催化剂GII可以在烯酸盐转化中引起意想不到的副作用. 素连接体攻击烯酸盐,导致卡巴尼的形成和催化剂的失活,影响合成和聚合物脱聚合.
科学领域:
- 有机化学 有机化学
- 聚合物化学 聚合物化学
- 催化剂是一种催化剂.
背景情况:
- 烯酸盐转化提供了多样化的应用,包括合成有价值的α,β不和 Ester和脱聚合不和聚合物.
- 格鲁布斯催化剂GII是这些转变中的关键催化剂.
研究的目的:
- 为了研究涉及格鲁布斯催化剂GII在烯酸盐转化中的意外副作用.
- 阐明这些副作用的机制及其对催化过程的影响.
主要方法:
- 使用格鲁布斯催化剂GII进行了详细的机制研究.
- 对反应途径的分析,包括carbanion形成和随后的反应.
主要成果:
- 观察到有证据表明素联结体 (PCy3) 对烯酸烯酸的攻击.
- 这种攻击会产生一种反应性carbanion中间体.
- 卡巴尼翁参与了迈克尔的加法,质子抽象和催化剂失活路径.
结论:
- 意外的副作用可能会发生在Grubbs催化剂GII在烯酸盐转化过程中.
- 可变的金属啡复合物催化与缺电子烯的反应可能表现出类似的反应性.
- 了解这些途径对于优化烯酸盐转化和相关的催化过程至关重要.
相关概念视频
Olefin Metathesis Polymerization: Overview
2.8K
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
2.8K
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
2.3K
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
2.3K
Acid Halides to Alcohols: Grignard Reaction
3.4K
Organomagnesium halides, commonly known as Grignard reagents, convert acid halides to tertiary alcohols. The reaction requires two equivalents of the Grignard reagent and proceeds via a ketone intermediate.
Grignard reagents are a source of carbanions and function as nucleophiles. The mechanism begins with the nucleophilic attack by the carbanion at the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs,...
Grignard reagents are a source of carbanions and function as nucleophiles. The mechanism begins with the nucleophilic attack by the carbanion at the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs,...
3.4K
Preparation of Alkynes: Alkylation Reaction
12.8K
Introduction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
12.8K
Esters to Alcohols: Grignard Reaction
6.8K
The reaction of an ester with a Grignard reagent, followed by hydrolysis of the magnesium alkoxide salt in aqueous acid, yields a tertiary alcohol. In the case of formate esters, secondary alcohols are formed.
The reaction requires two equivalents of the Grignard reagent and introduces two identical alkyl groups, derived from the Grignard reagent, bonded to the hydroxyl-bearing carbon of the alcohol.
The reaction follows the typical nucleophilic acyl substitution mechanism. The Grignard...
The reaction requires two equivalents of the Grignard reagent and introduces two identical alkyl groups, derived from the Grignard reagent, bonded to the hydroxyl-bearing carbon of the alcohol.
The reaction follows the typical nucleophilic acyl substitution mechanism. The Grignard...
6.8K
Preparation of Carboxylic Acids: Carboxylation of Grignard Reagents
6.5K
Carboxylic acids can be prepared by the carboxylation of Grignard reagents (RMgX). This method is convenient for converting alkyl (primary, secondary or tertiary), vinyl, benzyl, and aryl halides to carboxylic acids with one additional carbon than the starting RMgX.
6.5K


