实际合成和迪尔斯-阿尔德化学 [4]dendralene 的
Alan D Payne1, Anthony C Willis, Michael S Sherburn
1Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia.
Journal of the American Chemical Society
|September 1, 2005
概括
新的多米诺循环添加反应有效地从简单的构建块中创建复杂的分子. 这些反应在一个步骤中形成多个环和碳键,由易斯酸控制.
科学领域:
- 有机化学 有机化学
- 合成化学 合成化学
- 催化剂是一种催化剂.
背景情况:
- 多米诺反应提供了高效的合成路径,通过在一个中连续形成多个键.
- 交叉结合的多烯,像树枝烯一样,在循环添加反应中是多功能但具有挑战性的基质.
- 控制聚环添加中的区域选择性和立体选择性对于复杂分子合成至关重要.
研究的目的:
- 开发使用 [4]dendralene 的新型原子效率高的多米诺循环加法序列.
- 探索在单个合成操作中生成多个立体中心和环.
- 为了研究对对交叉结合系统的二烯基添加物中位点选择性的控制.
主要方法:
- 使用 [4]dendralene,最简单的交叉合四烯,作为一个关键反应剂.
- 采用多米诺循环加法策略来构建复杂的分子架构.
- 研究了使用简单的易斯酸来指导反应的位点选择性.
主要成果:
- 报告了令人惊叹的新型原子效率高的多米诺循环加法序列.
- 在一次合成操作中形成了多达8个立体中心,3个新环和6个碳-碳键.
- 通过使用易斯酸催化剂,证明有效控制二烯基基添加的位点选择性.
结论:
- 开发的多米诺循环加法序列为构建高度复杂的分子提供了强大而高效的方法.
- 易斯酸催化能够精确控制涉及交叉结合四烯的反应中的反应性和选择性.
- 这些发现为合成具有高立体化学复杂性的复杂有机结构开辟了新的途径.
相关概念视频
Structure of Conjugated Dienes
Introduction
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
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.
Diels–Alder Reaction: Characteristics of Dienes
The Diels–Alder reaction brings together a diene and a dienophile to form a six-membered ring. Both components have unique characteristics that influence the rate of the reaction.
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is more stable, the...
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is more stable, the...
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.


