金催化三组件合:基的氧化氧化化
Asa D Melhado1, William E Brenzovich, Aaron D Lackner
1Department of Chemistry, University of California, Berkeley, California 94720, USA.
Journal of the American Chemical Society
|June 19, 2010
概括
一种新的黄金 (I) 催化反应有效地结合了基,酸和氧核友. 这种方法提供了一条通往β-乙烯,和酒精的多功能途径.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 合成方法论 合成方法论
背景情况:
- 为功能化有机分子开发高效的合成路径在化学中至关重要.
- 黄金催化已经成为各种有机转换的强大工具.
- 的选择性功能化仍然是一个重要的合成挑战.
研究的目的:
- 开发一种新的三元合反应.
- 为了利用终端基,酸和氧核友.
- 为了建立一个有效的合成β-基替代氧化化合物.
主要方法:
- 采用双核金 (((I) 化物复合物作为催化剂.
- 使用Selectfluor作为静态度氧化剂.
- 探索氧核友的范围,包括酒精,碳酸和水.
主要成果:
- 终端基,酸和氧核友的成功三元组合.
- 证明反应的效率和多功能性.
- 从简单的原料中合成β-乙烯,和酒精.
结论:
- 开发的黄金催化反应为合成β-烯氧化化合物提供了一种高效和实用的方法.
- 这种方法扩大了终端和酸的合成效用.
- 这种反应为有机合成提供了一种有价值的新工具.
相关概念视频
01:46Oxidative Cleavage of Alkenes: Ozonolysis
In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
02:36Oxymercuration-Reduction of Alkenes
Oxymercuration–reduction of alkenes is one of the major reactions converting alkenes to alcohols. It involves the hydration of alkenes with mercuric acetate in a mixture of tetrahydrofuran and water, forming an organomercury adduct. This is followed by a demercuration step in which the adduct is reduced to an alcohol using sodium borohydride.
02:04Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
02:21Oxidation of Alkenes: Syn Dihydroxylation with Potassium Permanganate
Alkenes can be dihydroxylated using potassium permanganate. The method encompasses the reaction of an alkene with a cold, dilute solution of potassium permanganate under basic conditions to form a cis-diol along with a brown precipitate of manganese dioxide.
02:01Alkynes to Carboxylic Acids: Oxidative Cleavage
Alkynes undergo oxidative cleavage in the presence of oxidizing reagents like potassium permanganate and ozone. The triple bond — one σ bond and two π bonds — is completely cleaved, and the alkyne is oxidized to carboxylic acids. When warm and basic aqueous potassium permanganate is used as an oxidizing agent, alkynes are first converted to carboxylate salts via an unstable α-diketone intermediate. Further, a mild acid treatment protonates the carboxylate anions generating free carboxylic acid...