通过异循环设计提高动态迈克尔反应的平衡
Alex E Crolais1, Neil D Dolinski2, Nicholas R Boynton2
1Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States.
Journal of the American Chemical Society
|June 23, 2023
概括
研究人员使用异醇基因开发了新的无催化剂动态-迈克尔受体. 这些受体显著增强平衡常数,在室温下实现强大的动态共价网络和线性聚合物.
科学领域:
- 材料科学
- 聚合物化学
- 有机化学
背景情况:
- 动态-迈克尔 (tM) 反应在材料科学和制药领域具有价值.
- 低平衡常量 (Keq) 限制了没有催化剂的tM反应的全部潜力.
- 现有的动态共价材料往往缺乏足够的机械强度.
研究的目的:
- 开发具有增强平衡常数的新型无催化剂,室温动态的迈克尔受体.
- 创建具有改进性质的新动态共价网络和线性聚合物.
- 调查受体结构,Keq和材料性能之间的关系.
主要方法:
- 含有异醇基因的迈克尔受体的合成.
- 调节接受器的电子特性以调节Keq.
- 动态共价网络和线性聚合物的特征.
- 合成材料的机械测试
主要成果:
- 与非循环类似物相比,Keq增加了2个数量级 (∼1000到∼100,000 M-1).
- 开发了基于异佐的二极管受体,用于网络和聚合物形成.
- 证明了可定制的热力学性能和增强的机械强度.
- 由于较高的 Keq,使线性聚合物的溶液状态形成.
结论:
- 基于异佐的迈克尔受体显著改善了反应平衡.
- 增强的 Keq 导致更强大的机械动态共价材料.
- 这些新的受体有助于开发先进的功能性聚合物和网络.
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
相关概念视频
01:08Conjugate Addition of Enolates: Michael Addition
2.6K
The attack of a nucleophile at the β carbon of an α,β-unsaturated carbonyl compound is called conjugate addition. Conjugate addition reactions of active methylene compounds, such as β-diketones, β-keto esters, β-keto nitriles, and α-nitro ketones, are called Michael addition reactions.
2.6K
01:17Thermal Electrocyclic Reactions: Stereochemistry
2.0K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.0K
01:29Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
4.7K
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
4.7K
01:28Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
3.9K
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
3.9K
02:20Dynamic Equilibrium
52.0K
A reversible chemical reaction represents a chemical process that proceeds in both forward (left to right) and reverse (right to left) directions. When the rates of the forward and reverse reactions are equal, the concentrations of the reactant and product species remain constant over time and the system is at equilibrium. A special double arrow is used to emphasize the reversible nature of the reaction. The relative concentrations of reactants and products in equilibrium systems vary greatly;...
52.0K
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
3.2K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
3.2K