催化型的分子内化,用未被激活的烯酸对醇进行了化
Cong Liu1, Xiaoqing Han, Xiang Wang
1P. M. Gross Chemical Laboratory, Duke University, Durham, North Carolina 27708-0346, USA.
Journal of the American Chemical Society
|March 25, 2004
概括
催化使得从2-基因 indoles 的碳醇衍生物的高效合成. 这种方法是多用途的,可以容忍各种替代物,并且适用于未受保护的内醇和相关的异环.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 异环化学 异环化学
背景情况:
- 印衍生物是药物化学中的关键支架.
- 有效的合成路径,以复杂的醇基异环,是高度寻求的.
- 催化为C-C键形成提供了独特的反应性.
研究的目的:
- 开发一种新的催化循环化方法,用于2-基.
- 探索这种催化系统的范围和局限性.
- 为了阐明反应机制.
主要方法:
- 1 - 甲基 - 2 - 3 - 4 - 丁烯 - 醇与化 (PtCl2) 催化剂的反应.
- 用二氧化作为溶剂与微量盐酸 (HCl) 的使用.
- 机械研究涉及对复杂烯的核友性攻击.
主要成果:
- 4,9-二甲基-2,3,4,9-四水-1H-碳醇的高产量 (92%) 隔离.
- 在乙烯链上的替代品的耐受性.
- 成功合成了四-β-卡尔博林.
- 观察到对2 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 的排他性的6内分触发区域选择性.
- 证明适用于未受保护的内膜的应用.
结论:
- 催化循环化提供了一条有效的途径,以替代碳素醇和相关的异环循环.
- 该协议是强大的,多功能,并通过核爱性攻击的印在协调的olefin.通过进行.
- 这种方法扩大了合成工具包,用于访问复杂的含异环.
相关概念视频
Acid Halides to Carboxylic Acids: Hydrolysis
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 acid...
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 acid...
Nitriles to Ketones: Grignard Reaction
Organomagnesium halides, commonly known as Grignard reagents, convert nitriles to ketones and proceed through a nucleophilic acyl substitution. Nitriles react with a Grignard reagent, followed by an aqueous acid, to yield ketones. The reaction introduces a new carbon–carbon bond. The alkyl–magnesium bond in the Grignard reagent is highly polar, so the alkyl carbon develops a carbanionic character and acts as a nucleophile.
The mechanism begins with a nucleophilic attack by the Grignard reagent...
The mechanism begins with a nucleophilic attack by the Grignard reagent...
Amines to Amides: Acylation of Amines
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
α-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.’
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Acetoacetic ester synthesis is a method to obtain ketones from alkyl halides and β-keto esters. The reaction occurs in the presence of an alkoxide base that abstracts the acidic proton of the β-keto esters. The step results in an enolate ion which is doubly stabilized. The enolate then reacts with an alkyl halide via the SN2 process to produce an alkylated ester intermediate with a new C–C bond. The hydrolysis of the intermediate, followed by acidification, results in an alkylated β-keto acid.
Reactions of Carboxylic Acids: Introduction
Carboxylic acids possess an acidic –COOH functional group. The acidity can be attributed to the resonance stabilization of their conjugate base, wherein the negative charge is delocalized over both oxygen atoms.


