在醇中,N-N 键裂变是由 bis ((imino) pyridine 铁复合物的铁复合物引起的
Sarah K Russell1, Emil Lobkovsky, Paul J Chirik
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.
Journal of the American Chemical Society
|January 9, 2009
概括
铁二化合物复合物与二甲基发生反应,分裂N-N键,形成铁和伊胺复合物. 这种反应通过铁基中间体和 [4pi + 2pi] 循环添加路径进行.
科学领域:
- 有机金属化学 有机金属化学
- 协调化学 协调化学
- 固定的研究 固的研究
背景情况:
- 双胺连接物对于稳定反应性铁复合物至关重要.
- 铁复合物在催化过程中被研究为贵金属的替代品.
- 协调二 (N2) 的反应性是固化的关键.
研究的目的:
- 为了研究一个 bis ((imino) pyridine 铁二化合物的反应与单位替代 diazoalkanes.
- 阐明铁二复合体中N-N键裂解的机制.
- 探索这种反应的合成实用性,以产生新的铁复合体.
主要方法:
- (iPr) PDI) Fe (N2) 2与各种单替代醇 (N2CHR) 的反应.
- 在23°C的-d6中进行光谱分析 (NMR).
- 机械学研究包括动力学分析和中间陷 (隐含).
主要成果:
- 在添加了二氧化时,N-N键发生了快速裂变.
- 铁烯 (((iPr) PDI) FeNCR) 和伊胺 (((iPr) PDI) FeHNCHR) 复合物的形成.
- 烯酸也被裂开,产生相同的产品.
- 机理学研究表明,一种涉及铁基和 [4pi + 2pi] 循环添加的途径.
结论:
- 单位置换的醇能够有效地切割铁二化合物的N-N键.
- 反应通过一个复杂的机制进行,涉及循环添加和迁移.
- 这提供了一条合成途径,以从二基前体中获得铁和胺复合物.
相关概念视频
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para position.
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
Oxidation of Phenols to Quinones
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Diazonium Group Substitution: –OH and –H
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
Treating arylamines with nitrous acid gives aryldiazonium salts that are effective substrates in nucleophilic aromatic substitution reactions. The diazonio group in these salts can be easily displaced by different nucleophiles, yielding a wide variety of substituted benzenes. The leaving group departs as nitrogen gas, and this easy elimination is the driving force for the substitution reaction.
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...
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...


