用中性的易斯酸进行可逆C-H键化
Thaddäus Thorwart1, Lutz Greb1
1Ruprecht-Karls-Universität Heidelberg, Anorganisch-Chemisches Institut Im Neuenheimer Feld 270 Heidelberg 69120 Germany greb@uni-heidelberg.de.
Chemical science
|October 20, 2023
概括
研究人员使用挫败的易斯对 (FLP) 开发了一种新的,可逆的-碳键形成方法. 这一突破使自发的C-H化和解构成为可能,为合成化学提供了一条新的途径.
科学领域:
- 有机化学 有机化学
- 有机化学 有机化学
- 催化剂是一种催化剂.
背景情况:
- -碳键的形成在合成中至关重要,但通常需要恶劣的条件或不可逆转的反应.
- 现有的方法通常涉及金属化核,活性试剂或过渡金属催化.
- 可逆的C-H与中性西兰的化仍然是合成化学的一个欠发达的领域.
研究的目的:
- 开发一种使用中性西兰酸进行可逆C-H化的新方法.
- 探索自发C-H化及其随后解构的机制.
- 建立一个对现有的不可逆转的C-H键化协议的补充方法.
主要方法:
- 使用的双 () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () () ()
- 采用计算和实验技术来阐明反应机制.
- 研究了使用silaphilic捐赠者的氨酸盐产品的解构.
主要成果:
- 实现了异环和终端基因的自发C-H化.
- 确定了一种挫败的易斯对 (FLP) 机制,驱动着化反应.
- 通过向酸盐产品添加silaphilic捐赠体来证明可逆的C-H键重组.
- 在FLP激活下观察到N-甲基醇的活性变化.
结论:
- 开发了一种新的,可逆的C-H化和解构策略.
- 丧的易斯对 (FLP) 方法为传统方法提供了更温和,更通用的替代方案.
- 这项工作扩大了-碳键形成和功能化的合成实用性.
相关概念视频
Preparation and Reactions of Sulfides
4.9K
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
4.9K
Acid Halides to Carboxylic Acids: Hydrolysis
2.7K
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
2.7K
Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
3.8K
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...
3.8K
Acid Halides to Alcohols: LiAlH4 Reduction
2.9K
Acid halides are reduced to alcohols in the presence of a strong reducing agent like lithium aluminum hydride.
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
2.9K
Acid Halides to Esters: Alcoholysis
2.9K
Alcoholysis is a nucleophilic acyl substitution reaction in which an alcohol functions as a nucleophile. Acid halides react with alcohol to produce esters. The mechanism proceeds in three steps:
2.9K
Acid Halides to Ketones: Gilman Reagent
2.9K
Lithium dialkyl cuprate, also known as Gilman reagents, selectively reduces acid halides to ketones. The acid chloride is treated with Gilman reagent at −78 °C in the presence of ether solution to produce a ketone in good yield.
As shown below, the mechanism proceeds in two steps. First, one of the alkyl groups of the reagent acts as a nucleophile and attacks the acyl carbon of the acid chloride to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen...
As shown below, the mechanism proceeds in two steps. First, one of the alkyl groups of the reagent acts as a nucleophile and attacks the acyl carbon of the acid chloride to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen...
2.9K


