有效和实用的Ag催化循环添加剂在arylimines和Danishefsky diene之间
Nathan S Josephsohn1, Marc L Snapper, Amir H Hoveyda
1Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Journal of the American Chemical Society
|April 3, 2003
概括
这项研究引入了一种高效的白银催化非对称循环添加反应,使用Danishefsky diene和aryl imines. 该方法实现了高的enantioselectivity和产量,利用易于准备的性联体,并提供无溶剂的选项.
科学领域:
- 有机化学 有机化学
- 不对称的催化剂.
- 循环添加反应的反应
背景情况:
- 丹尼什夫斯基二烯是有机合成中的多功能试剂.
- 循环载荷管的不对称合成对于药物开发至关重要.
- 有效的催化方法是必要的,以对enantioselective循环添加.
研究的目的:
- 开发一种高效的Ag催化不对称的Danishefsky二烯添加到aryl imines.
- 为了在形成循环载荷管道中实现高的enantioselectivity和产量.
- 探索实际的反应条件,包括无溶剂和耐空气的协议.
主要方法:
- 使用一种白银 (Ag) 催化不对称的循环添加反应.
- 采用丹尼舍夫斯基二烯和各种烯胺作为基质.
- 开发并使用一种易于制备的性联结体,该联结体来自像i-Leu.u.等廉价材料.
- 在低温 (4摄氏度) 和低催化剂负荷 (0.1-1摩尔%) 的情况下研究的反应.
主要成果:
- 在循环载荷管道中达到≥89%的高反体过量 (ee).
- 获得的高孤立产量≥85%.
- 在无溶剂条件下和在空气中证明了成功的反应.
- 报告了一种可回收的,第一代支持的性催化剂,经过五次成功循环.
结论:
- 已经建立了一个高效和实用的Ag催化不对称循环加法方法.
- 开发的性连接体和催化系统对于合成有价值的循环载荷导管是有效的.
- 可回收催化剂和简化反应条件的潜力提高了这种方法的适用性.
相关概念视频
[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.
Diels–Alder Reaction: Characteristics of Dienophiles
In a Diels–Alder reaction, the diene is usually an electron-rich system and acts as a nucleophile, whereas the dienophile is electron-deficient and functions as an electrophile. Much like the diene, the nature of the dienophile significantly impacts the outcome of the reaction.
Characteristics of Dienophiles
Generally, the best dienophiles are alkenes containing electron-withdrawing substituents such as carbonyl, nitrile, and nitro groups. The feasibility of a Diels–Alder reaction depends on...
Characteristics of Dienophiles
Generally, the best dienophiles are alkenes containing electron-withdrawing substituents such as carbonyl, nitrile, and nitro groups. The feasibility of a Diels–Alder reaction depends on...


