一种强大的催化剂,用于合成高功能有机碳酸盐
Christopher J Whiteoak1, Nicola Kielland, Victor Laserna
1Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona, Spain.
Journal of the American Chemical Society
|January 11, 2013
概括
一个新的催化剂有效地将环氧化物和二氧化碳转化为有机碳酸盐. 这种可持续的方法在温和条件下使用低量的催化剂,使用安全,负担得起的金属.
科学领域:
- 有机金属化学 有机金属化学
- 绿色化学 绿色化学
- 催化剂是一种催化剂.
背景情况:
- 有机碳酸盐是有价值的化学中间体.
- 有机碳酸盐的传统合成通常涉及恶劣的条件或有毒试剂.
- 开发高效和可持续的催化方法至关重要.
研究的目的:
- 开发一种高活性和选择性基催化剂,用于有机碳酸盐合成.
- 探索使用环氧化物和二氧化碳作为可持续原料.
- 调查催化剂在活性,基质范围和功能组耐受性方面的性能.
主要方法:
- 一个含有氨基三酸连接体的复合物的合成.
- 在最佳条件下,各种环氧化物与二氧化碳的催化反应.
- 使用标准光谱技术 (例如NMR,GC-MS) 分析反应产品.
主要成果:
- 催化剂表现出前所未有的高活性,初始周转频率 (TOF) 高达36,000小时.
- 催化系统表现出广泛的基板范围和出色的功能组耐受性.
- 在温和的条件下,反应在低催化剂负载下有效地进行.
- 该过程利用了一个廉价,丰富且无毒的金属来源.
结论:
- 开发的氨基三酸复合物代表了一种高度有效的催化剂,用于从环氧化物和CO2中合成功能性有机碳酸盐.
- 该协议为现有方法提供了一种可持续,高效和工业可行的替代方案.
- 催化剂的性能突显了地球上丰富的金属在绿色催化应用中的潜力.
相关概念视频
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
Acid-Catalyzed Aldol Addition Reaction
The aldol reaction of a ketone under acidic conditions successfully forms an unsaturated carbonyl as the final product instead of an aldol. The acid-catalyzed aldol reaction is depicted in Figure 1.
Oxidations of Aldehydes and Ketones to Carboxylic Acids
Oxidation of aldehydes and ketones results in the formation of carboxylic acids. Aldehydes, bearing hydrogen next to the carbonyl group, are easily oxidized compared to ketones. This is because an aldehydic proton can easily be abstracted during oxidation.
Aldehydes readily undergo oxidation in strong oxidizing agents such as potassium permanganate and chromic acid. The oxidation can also be carried out using mild oxidizing agents such as silver oxide. In fact, aldehydes can be easily oxidized...
Aldehydes readily undergo oxidation in strong oxidizing agents such as potassium permanganate and chromic acid. The oxidation can also be carried out using mild oxidizing agents such as silver oxide. In fact, aldehydes can be easily oxidized...
Preparation of Aldehydes and Ketones from Nitriles and Carboxylic Acids
Although it is possible to reduce a carboxylic acid to an aldehyde, strong reducing agents, like lithium aluminum hydride (LAH), prohibit a controlled reduction, instead causing the generated aldehyde to instantly over-reduce to a primary alcohol.
Reducing carboxylic acid derivatives like acyl chlorides (RCOCl), esters (RCO2R′), and nitriles (RCN) using milder aluminum hydride agents like lithium tri-tert-butoxyaluminum hydride [LiAlH(O-t-Bu)3] and diisobutylaluminum hydride [DIBAL-H] allows...
Reducing carboxylic acid derivatives like acyl chlorides (RCOCl), esters (RCO2R′), and nitriles (RCN) using milder aluminum hydride agents like lithium tri-tert-butoxyaluminum hydride [LiAlH(O-t-Bu)3] and diisobutylaluminum hydride [DIBAL-H] allows...
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.
Preparation of Carboxylic Acids: Carboxylation of Grignard Reagents
Carboxylic acids can be prepared by the carboxylation of Grignard reagents (RMgX). This method is convenient for converting alkyl (primary, secondary or tertiary), vinyl, benzyl, and aryl halides to carboxylic acids with one additional carbon than the starting RMgX.


