一种用铜催化方法,用于将格里纳德试剂选择性添加到环烯中
1Brown Laboratories, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
Journal of the American Chemical Society
|November 28, 2002
概括
将铜催化格里纳德试剂添加到环烯中,会产生奇拉四元中心. 这种方法使得能够合成具有卓越的二聚体选择性的高度功能化的环烯.
科学领域:
- 有机金属化学 有机金属化学
- 有机合成 有机合成
- 立体选择性反应
背景情况:
- 循环烯是具有独特反应性的应变循环烯.
- 开发用于功能化环二烯的立体选择性方法对于复杂分子合成至关重要.
- 格里纳德试剂是有机化学中的多功能核.
研究的目的:
- 开发一种铜催化方法,将格里格纳德试剂添加到环烯中.
- 为了研究加法反应的立体化学结果.
- 探索生成的环金属中间体的实用性,以进一步功能化.
主要方法:
- 用铜催化添加格林纳德试剂 (基,基,基化物) 到1-基-3-基甲基cyclopropenes及其MOM.
- 使用光谱学方法分析二聚体选择性.
- 介质环金属与各种电友的反应.
主要成果:
- 添加发生在循环烯环上的现有替代剂的同步.
- 对于广泛的格里格纳德试剂,可以实现出色的立体选择性.
- 反应成功地产生了性全碳四元中心.
- 循环金属中间体的后续反应产生高度功能化的循环.
结论:
- 已经建立了一种新且高效的Cu-催化方法,用于对环烯的立体选择性格里纳德添加.
- 这种方法提供了获取有价值的奇拉环烯基建材的途径.
- 开发的协议为构建复杂的有机分子提供了一个强大的工具.
相关概念视频
Acid Halides to Ketones: Gilman Reagent
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 double...
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 double...
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...
Cycloaddition Reactions: Overview
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
Acid Halides to Alcohols: Grignard Reaction
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,...
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.
Cycloaddition Reactions: MO Requirements for Thermal Activation
Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.

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