氧化还原活性 bis(imino) 乙烯联体类的固体导向功能化:实验和理论调查
Daniel A Evans1, Ignacio Vargas-Baca, Alan H Cowley
1Department of Chemistry and Biochemistry, The University of Texas at Austin , Austin, Texas 78712, United States.
Journal of the American Chemical Society
|September 6, 2013
概括
立体阻碍指导了氧化还原活性 bis(imino) 乙纳 (BIAN) 连接体的功能化. 根据硬质体量,反应通过激进的脱氧化或核性化进行,提供新的合成路径.
科学领域:
- 有机化学 有机化学
- 协调化学 协调化学
- 计算化学计算化学
背景情况:
- 双氨酸乙 (BIAN) 连接物具有氧化还原活性,并且可以在固态上调节.
- 了解功能化途径对于连接体设计至关重要.
研究的目的:
- 为了探索Ar-BIAN配体的固态定向功能化.
- 阐明Ar-BIAN功能化路径的机制.
主要方法:
- Ar-BIAN衍生品的合成和表征.
- 单晶X射线衍射用于结构确定.
- 电子偏磁共振 (EPR) 光谱仪用于反应监测.
- 密度函数理论与分散 (DFT-D) 计算用于机械洞察力.
主要成果:
- 在N-C-C-N碎片周围的无菌拥堵决定了功能化途径.
- 确定了两种不同的途径:激进的脊柱脱氧化和核性 imine C-alkylation.
- 新型Ar-BIAN衍生物的结构 (14-19) 通过X射线衍射证实.
结论:
- 绝缘控制是指导Ar-BIAN功能化的关键因素.
- DFT-D计算成功地解释了观察到的反应路径和驱动力.
- 这项研究为设计具有可预测反应性的功能化BIAN配体提供了一个框架.
相关概念视频
Amines to Amides: Acylation of Amines
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
Preparation of Amines: Reductive Amination of Aldehydes and Ketones
Carbonyl compounds and primary amines undergo reductive amination first to produce imines, followed by secondary amines in the same reaction mixture, using selective reducing agents like sodium cyanoborohydride or sodium triacetoxyborohydride. Reductive amination produces different degrees of substitution of amines depending on the starting amine substrate.
Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
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...
Aldehydes and Ketones with Amines: Imine and Enamine Formation Overview
Primary amines react with carbonyl compounds—aldehydes and ketones—to generate imines. Imines consist of a C=N double bond and are named Schiff bases after its discoverer—the German chemist Hugo Schiff. On the other hand, secondary amines react with carbonyl compounds to give enamines. In enamines, the presence of a C=C double bond adjacent to the nitrogen atom leads to the delocalization of the lone pair.


