通过 (alpha-diimine) PdR+PdR+PdR+PdR+PdR+PdR (α-diimine) 的方法将西乙烯乙烯与烯酸盐共聚合
1Department of Chemistry, The University of Chicago, Illinois 60637, USA.
Journal of the American Chemical Society
|September 14, 2006
概括
这项研究表明,催化剂可以对烯酸和乙烯酸乙进行共聚合. 由此产生的共聚物可以被脱化,产生有价值的乙烯基醇共聚物.
科学领域:
- 有机金属化学 有机金属化学
- 聚合物科学 聚合物科学
- 催化剂是一种催化剂.
背景情况:
- 奥莱芬聚合是聚合物化学的基石.
- 将各种各样的单体纳入聚合物链仍然是一个挑战.
- 丝乙烯乙为聚合物修饰提供了独特的功能.
研究的目的:
- 用催化剂研究olefins和silyl vinyl ethers的共聚变.
- 为了阐明这种新型共聚合反应的机制.
- 探索由此产生的共聚合物在进一步功能化方面的潜力.
主要方法:
- 使用 (α-二胺) PdMe+催化剂进行共聚合反应.
- 采用各种西乙烯和1-hexene作为单体.
- 使用光谱技术分析聚合物结构.
- 进行了控制实验,以排除替代机制.
主要成果:
- 成功实现了1-hexene与西乙烯乙烯 (R=tBu,SiMe3) 的共聚合.
- 提出了一个插入/链路行走机制,与阴离子或基因通路不同.
- 证明共聚合物可以被脱化以产生乙烯基醇共聚合物.
- 在共聚物结构中确定了主要的共聚物体合并模式.
结论:
- (α-二胺) PdMe+催化剂有效地调解了烯酸和乙烯基乙烯的共聚变.
- 拟议的插入/链行走机制为反应途径提供了洞察力.
- 由此产生的共聚合物的脱化提供了一条通往功能性聚 (烯-共乙烯醇) 材料的途径.
相关概念视频
Preparation of Diols and Pinacol Rearrangement
Compounds bearing two hydroxyl groups are known as diols. When the hydroxyl groups are located on adjacent carbon atoms, the diols are called vicinal diols or glycols. Under acidic conditions, vicinal diols undergo a specific reaction called pinacol rearrangement.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
Preparation of Acid Anhydrides
One of the methods for preparing symmetrical or unsymmetrical acid anhydrides involves the treatment of acid chlorides with the sodium salt of carboxylic acids. The reaction proceeds via a nucleophilic acyl substitution.
The carboxylate ion acts as a nucleophile that attacks the carbonyl carbon of the acid chloride to form a tetrahedral intermediate. Subsequently, the re-formation of the carbonyl group with the loss of the chloride ion as a leaving group leads to the formation of an acid...
The carboxylate ion acts as a nucleophile that attacks the carbonyl carbon of the acid chloride to form a tetrahedral intermediate. Subsequently, the re-formation of the carbonyl group with the loss of the chloride ion as a leaving group leads to the formation of an acid...
α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
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 bromine molecule...
Vicinal Diols via Reductive Coupling of Aldehydes or Ketones: Pinacol Coupling Overview
Wilhelm Rudolph Fittig discovered the pinacol coupling reaction in 1859. It is a radical dimerization reaction and involves the reductive coupling of aldehydes or ketones in the presence of hydrocarbon solvent to yield vicinal diols.
Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction
The radical dimerization of ketones or aldehydes gives vicinal diols through a pinacol coupling reaction. However, the behavior of titanium metals used for the reaction as a source of electrons is unusual. When the reaction is carried out in the presence of titanium, diols can be isolated at low temperatures. Else titanium further reacts with diols, forming alkenes through the McMurry reaction.
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,...
![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)

