通过1,7-enynes的ene-type循环合成,通过一个阴离子BINAP-palladium ((II) 复合物催化,高分离选择性类合成
1Department of Applied Chemistry, Tokyo Institute of Technology, Tokyo 152-8552, Japan.
Journal of the American Chemical Society
|April 17, 2003
概括
研究人员开发了一种新方法,以高精度合成氨酸环. 这种催化过程产生了具有优异产量和纯度的复杂结构,促进了有机合成.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 不对称的合成方法
背景情况:
- 奎诺林衍生物是药物化学中的重要支架.
- 开发复杂氨酸的enantioselective合成方法仍然是一个挑战.
研究的目的:
- 报道了第一个六个成员环诺林的高度反选择性合成.
- 作为催化剂,利用一个阳离子BINAP- (II) 复合物.
主要方法:
- 催化不对称合成使用一个阴离子BINAP- (II) 复合体.
- 以四等碳中心或螺旋环结构的林产品的形成.
主要成果:
- 为林产品实现了定量产量.
- 获得了优异的反反选择性,具有>99%的反反体过量 (ee).
- 成功合成了具有四级碳中心或螺旋环图案的诺林.
结论:
- 开发的方法为复杂的素结构提供了一种高效和选择性途径.
- 这种催化系统对于构建具有挑战性的分子架构是有效的.
相关概念视频
Preparation of Alkynes: Alkylation Reaction
Introduction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction
α-Substituted ketones or aldehydes can be synthesized from enamines by the Stork enamine reaction, named after its pioneer Gilbert Stork. Enamines are useful synthetic intermediates where the lone pair on nitrogen is in conjugation with the C=C bond. They resemble enolate ions, as the resonance forms of both species have a nucleophilic α carbon.
Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.


