一氧化碳在碳化合物复合体中与悬挂易斯酸进行了还原性合
Alexander J M Miller1, Jay A Labinger, John E Bercaw
1Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125, USA.
Journal of the American Chemical Society
|August 16, 2008
概括
素联体使独特的碳基离子反应能力. 添加化物形成了一种新型的氧碳,它不成比例地产生了C-C合产物.
科学领域:
- 有机金属化学 有机金属化学
- 协调化学 协调化学
背景情况:
- 与传统的素联体相比,素联体具有独特的电子和硬质性质.
- 碳基复合物是研究联体反应和催化转换的多功能平台.
研究的目的:
- 为了研究含有博联体的碳基离子的反应性.
- 通过化物添加形成的新型有机金属物种的特征.
- 为了探索减少的碳酸联体中C-C键形成的途径.
主要方法:
- 合成和表征与博联体的碳复合物.
- 与化物来源 (三乙化物和化物) 的反应.
- 反应产品的结晶和结构分析.
- 谱学研究 (NMR,IR) 来确认结构.
主要成果:
- 将化物添加到碳基离子中,得到一个玻氧碳素.
- 氧碳二元化,随后变得不成比例.
- 形成了一个结构上前所未有的boroxy(boroxymethyl) 碳,在减少的CO联体之间具有C-C键.
- 这种C-C合产物可以直接用2个等价的化物合成.
结论:
- 博联体促进碳基离子中独特的反应性,导致新的碳基物种.
- 这项研究表明,协调的一氧化碳连接体之间形成C-C键的新途径.
- 这些发现扩大了对有机金属碳素化学和还原性合过程的理解.
相关概念视频
01:27Vicinal 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.
01:22Alkenes 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.
01:09Aldehydes and Ketones to Alkanes: Wolff–Kishner Reduction
Wolff–Kishner reduction involves converting aldehydes and ketones to alkanes using hydrazine and a base. The reaction converts a carbonyl group to a methylene group. The method was independently discovered by N. Kishner in 1911 and L. Wolff in 1912. The reduction is carried out in high-boiling solvents such as ethylene glycol and diethylene glycol because heat is required to deprotonate the N–H proton in one of the reaction steps.
01:19α-Hydroxy Ketones via Reductive Coupling of Esters: Acyloin Condensation Overview
The pinacol and McMurry reactions involve the reductive coupling of ketones or aldehydes. Similarly, the bimolecular reductive coupling of two ester molecules in the presence of sodium metal in an aprotic solvent yields an α-hydroxy ketone product. The α-hydroxy ketone is also called acyloin, so the reaction is referred to as ‘acyloin condensation.’
02:36Oxymercuration-Reduction of Alkenes
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02:23Alcohols from Carbonyl Compounds: Reduction
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...