SmI2(H2O)n 通过质子合电子转移减少富含电子的胺
Scott S Kolmar1, James M Mayer1
1Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.
Journal of the American Chemical Society
|July 19, 2017
概括
二氧化物 (SmI2) 与水一起作为一种强大的减少剂,通过协同的质子合电子转移途径有效地减少酶. 这表明SmI2 ((H2O) n是强原子的供体,能够形成非常弱的C-H键.
科学领域:
- 有机化学
- 减氧化学
- 试剂开发
背景情况:
- 二氧化物 (SmI2) 是一种多用途的还原剂,主要用于碳化合物.
- 最近的研究强调了水中的SmI2和THF (SmI2(H2O) 作为一种有用的试剂.
- 胺是富含电子的基质,具有独特的还原挑战.
研究的目的:
- 通过使用SmI2(H2O) n来研究胺的减少.
- 阐明反应机制,区分各种电子和质子转移途径.
- 评估SmI2(H2O) n的原子捐赠能力.
主要方法:
- 使用SmI2(H2O) n进行胺的实验降解.
- 机械研究包括对初始外层电子转移,质子转移或基质协调的证据.
- 热化学分析以确定结合解离的自由能量 (BDFEs).
主要成果:
- SmI2 ((H2O) n有效地降低了胺.
- 机械实验强烈支持协同的质子合电子转移 (PCET) 途径.
- 形成的 C-H 键的 BDFE 值为 ~32 kcal mol-1,而水离子的 O-H BDFE 值为 ~26 kcal mol-1.
- 这些值表明SmI2(H2O) n是一个非常强的原子供体.
结论:
- SmI2 ((H2O) n是一种强大的电子丰富基质的还原剂,如胺.
- 而不是简单的外层电子转移或质子转移.
- 试剂形成非常弱的C-H键的能力强调了其作为原子供体的强度.
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
相关概念视频
01:26Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction
4.2K
α-Substituted ketones or aldehydes can be synthesized from enamines by the Stork enamine reaction, named after its pioneer Gilbert Stork. Enamines are useful synthetic intermediates where the lone pair on nitrogen is in conjugation with the C=C bond. They resemble enolate ions, as the resonance forms of both species have a nucleophilic α carbon.
4.2K
00:55Nitriles to Amines: LiAlH4 Reduction
4.8K
Nitriles are reduced to amines in the presence of strong reducing agents like lithium aluminum hydride through a typical nucleophilic acyl substitution. The reaction requires two equivalents of the reducing agent. The reducing agent acts as a source of hydride ions.
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
4.8K
01:14Aldehydes and Ketones with Amines: Enamine Formation Mechanism
8.1K
Enamine formation involves the addition of carbonyl compounds to a secondary amine through a series of reactions. The mechanism begins with the generation of carbinolamine, a nucleophilic attack followed by several proton transfer reactions. The hydroxyl group of the carbinolamine is converted into water to make a better leaving group that can push the reaction forward by eliminating a water molecule. In enamine formation, the last step involves the abstraction of a proton from the α carbon to...
8.1K
01:29Preparation of Amines: Reduction of Oximes and Nitro Compounds
4.7K
Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
4.7K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.9K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.9K
02:23Alcohols from Carbonyl Compounds: Reduction
12.7K
Reduction is a simple strategy to convert a carbonyl group to a hydroxyl group. The three major pathways to reduce carbonyls to alcohols are catalytic hydrogenation, hydride reduction, and borane reduction.
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
12.7K