由氧化碳离子拦截策略实现的从酒精和化物中直接合成乙烯
Dara T Curran1, Marcin Szydło1, Helge Müller-Bunz1
1Centre for Synthesis & Chemical Biology, School of Chemistry, University College Dublin Belfield Dublin 4 Ireland peter.byrne@ucd.ie kirill.nikitin@ucd.ie.
一种新的无化物还原性乙化方法,利用素和酸,从化物和酒精中合成乙. 这种高效的单工艺提供了卓越的功能组耐受性,为有机合成提供了新的途径.
科学领域:
- 有机化学 有机化学
- 合成方法论 合成方法论
背景情况:
- 在有机合成中,以太是关键的功能组.
- 传统的以太合成通常需要恶劣的条件或特定的减少剂,如化物或气.
研究的目的:
- 开发一种新,高效,无化物方法,从和酒精中合成.
- 建立一种减少性乙化策略,避免使用传统的减少剂.
主要方法:
- 一个两步,一的过程,涉及化物和酒精与素在酸的存在下发生反应.
- 形成中间α-(alkoxyalkyl) phosphonium盐,然后通过水解产生以太产品.
- 使用实验和计算证据对反应机制的研究,建议素对氧碳离子进行拦截.
主要成果:
- 对于以太产品,孤立产量在63%-92%之间.
- 该过程以望远镜,单的方式有效运行,不需要惰性大气条件.
- 该方法表现出优异的功能组耐受性,并且避免了需要化物或作为减少剂.
- 盐中间体的形成比乙烯酸形成更受青.
结论:
- 已经建立了一种新的,实用的和通用的净还原性以太化方法.
- 这种方法提供了一个简单的,没有化物的途径来合成各种和化.
- 这些发现为以太合成带来了重大进步,扩大了有机化学中的合成可能性.
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相关概念视频
Ethers from Alcohols: Alcohol Dehydration and Williamson Ether Synthesis
Ethers can be prepared from organic compounds by various methods. Some of them are discussed below,
Preparation of Ethers by Alcohol Dehydration
In this method, in the presence of protic acids, alcohol dehydrates to produce alkenes and ethers under different conditions. For example, in the presence of sulphuric acid, dehydration of ethanol at 413 K yields ethoxyethane, whereas it yields ethene at 443 K.
Ethers from Alkenes: Alcohol Addition and Alkoxymercuration-Demercuration
Ethers can also be prepared from alkenes through acid-catalyzed addition of alcohols and alkoxymercuration–demercuration.
Preparation of Ethers by Acid-Catalyzed Addition of Alcohol to Alkenes
The acid-catalyzed addition of alcohol to an alkene involves treating the alkene with an excess of alcohol in the presence of an acid catalyst to form an ether under suitable conditions. The hydrogen will add to the less substituted carbon so that the nucleophile can attack the more...
Preparation of Alcohols via Addition Reactions
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
Preparation of Epoxides
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
