通过Ti(IV) 介导的环氧酸合进行的宏微生态化: (-) - 达克提洛利德 (和赞帕诺利德) 的总合成
1Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA. hoye@chem.umn.edu
Journal of the American Chemical Society
|August 9, 2003
概括
本研究详细介绍了达克提洛利德的总合成,采用了一种新的Ti (IV) 介导的合策略. 关键步骤包括立体选择环形成和选择性氧化,用于构建复杂的分子架构.
科学领域:
- 有机化学 有机化学
- 合成化学 合成化学
- 自然产品的合成自然产品的合成
背景情况:
- 达克提洛利德是一种复杂的海洋天然产品,具有潜在的生物活性.
- 有效的合成路径对于进一步的生物评估和模拟开发至关重要.
研究的目的:
- 描述一种新且高效的达克提洛利德全合成方法.
- 展示用于构建复杂循环结构的创新合成方法.
主要方法:
- "无环氧化物"和碳素酸的介导的 (IV) 合 (巨乳化/分子间合).
- 质子催化,cis选择性合成一个4 - 甲基基酸环.
- 使用氨酸离子选择性氧化合醇.
- 迪涅维克二醇的环闭性转化.
- 介导的aza-aldol反应用于碳胺的形成.
主要成果:
- 成功完成了达克提洛利德的总合成.
- 作为一个关键的战略元素,Ti(IV) 介导合的演示.
- 开发用于钥匙圈系统的立体选择方法.
- 非循环碳胺分子组的高效构造.
结论:
- 描述的合成途径提供了一个可行的途径,以达克提洛利德.
- 采用的方法提供了复杂分子合成的多功能工具.
- 这项工作推动了自然产品合成领域的发展.
相关概念视频
01:57Preparation of Diols and Pinacol Rearrangement
Compounds bearing two hydroxyl groups are known as diols. When the hydroxyl groups are located on adjacent carbon atoms, the diols are called vicinal diols or glycols. Under acidic conditions, vicinal diols undergo a specific reaction called pinacol rearrangement.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
01:13Intramolecular Claisen Condensation of Dicarboxylic Esters: Dieckmann Cyclization
Dieckmann cyclization is an intramolecular Claisen condensation of diesters. The reaction occurs in the presence of a base and generates a cyclic β-ketoester as the final product. Commonly, 1, 6 and 1, 7-diesters are preferred substrates for the reaction since the generated five, and six-membered cyclic β-keto esters are particularly more stable.
01:11Aryldiazonium Salts to Azo Dyes: Diazo Coupling
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para position.
01:27Vicinal Diols via Reductive Coupling of Aldehydes or Ketones: Pinacol Coupling Overview
Wilhelm Rudolph Fittig discovered the pinacol coupling reaction in 1859. It is a radical dimerization reaction and involves the reductive coupling of aldehydes or ketones in the presence of hydrocarbon solvent to yield vicinal diols.
01:22Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction
The radical dimerization of ketones or aldehydes gives vicinal diols through a pinacol coupling reaction. However, the behavior of titanium metals used for the reaction as a source of electrons is unusual. When the reaction is carried out in the presence of titanium, diols can be isolated at low temperatures. Else titanium further reacts with diols, forming alkenes through the McMurry reaction.
01:14Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.