解锁脱氧化联体到金属电荷转移:使用碳酸的高效和氧中性化
Supeng Wu1, Ziqi Jiao1, Alex T Sung1
1Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States.
Journal of the American Chemical Society
|June 16, 2025
概括
这项研究引入了一种新型的光诱导反应,使用催化剂和碳酸盐进行立体选择性诺扎基 - 希亚马 - 基希结合. 这种方法直接形成同质醇,不需要外部氧化还原剂.
科学领域:
- 有机金属化学
- 摄影化学
- 有机合成
背景情况:
- 诺扎基 - 希亚马 - 基希 (NHK) 化是一种关键的碳-碳键形成反应.
- 现有的NHK协议通常需要石化试剂或恶劣的条件.
- 开发催化和较温和的NHK反应条件仍然是一个活跃的研究领域.
研究的目的:
- 报告一种新的Cr (III) 碳酸盐复合物的光诱导脱碳化对金属电荷转移 (LMCT) 反应.
- 为了证明这种光反氧催化对立体选择性诺扎基-希亚马-基希 (NHK) 结合的适用性.
- 开发一种直接利用碳酸的催化系统,消除对外部氧化还原剂的需求.
主要方法:
- 可见光启动的Cr (III) 碳酸盐复合物的光解离.
- 一个双基连接体支架的设计,以促进光解和合物添加.
- 使用碳酸作为基源的立体选择性诺扎基 - 希亚马 - 基希 (NHK) 合.
主要成果:
- 对Cr (III) 碳酸盐复合物的光诱导脱碳化LMCT的成功证明.
- 制备各种具有良好的产量和高 diastereoselectivities 的同质醇.
- 为开发的NHK协议确定有利的回合成断开.
结论:
- 开发的协议提供了使用碳酸盐的同质醇的直接和有效途径.
- 反应是通过合物到金属的电荷转移 (LMCT) 机制进行的,其中包括Cr (III) 碳酸盐物种.
- 这种光电还原方法为传统的NHK反应提供了更环保,更多功能的替代方案.
相关概念视频
Carboxylic Acids to Primary Alcohols: Hydride Reduction
3.4K
Carboxylic acids, upon reaction with strong reducing agents such as lithium aluminum hydride followed by hydrolysis, undergo reduction to form primary alcohols.
3.4K
Oxidations of Aldehydes and Ketones to Carboxylic Acids
4.2K
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...
4.2K
Preparation of Aldehydes and Ketones from Nitriles and Carboxylic Acids
3.7K
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]...
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]...
3.7K
Preparation of Aldehydes and Ketones from Carboxylic Acid Derivatives
2.8K
Aldehydes are more reactive than carboxylic acids and hence, can get over-reduced to alcohol in the presence of strong reducing agents. Therefore, carboxylic acids are inefficient in preparing aldehydes using LAH.
Carboxylic acid derivatives like acid chlorides and esters are more easily reducible than the corresponding acids. The derivatives reduce in the presence of mild reducing agents to give aldehydes. Aldehydes can also be prepared by Rosenmund reduction, that is, the reduction of...
Carboxylic acid derivatives like acid chlorides and esters are more easily reducible than the corresponding acids. The derivatives reduce in the presence of mild reducing agents to give aldehydes. Aldehydes can also be prepared by Rosenmund reduction, that is, the reduction of...
2.8K
Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
4.1K
By replacing an α-hydrogen with a halogen, acid-catalyzed α-halogenation of aldehydes or ketones yields a monohalogenated product
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...
4.1K
Acid Halides to Alcohols: Grignard Reaction
2.4K
Organomagnesium halides, commonly known as Grignard reagents, convert acid halides to tertiary alcohols. The reaction requires two equivalents of the Grignard reagent and proceeds via a ketone intermediate.
Grignard reagents are a source of carbanions and function as nucleophiles. The mechanism begins with the nucleophilic attack by the carbanion at the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs,...
Grignard reagents are a source of carbanions and function as nucleophiles. The mechanism begins with the nucleophilic attack by the carbanion at the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs,...
2.4K


