具有PC-Phos功能的催化-异不对称循环添加
Wenge Zhang1, Pei-Chao Zhang2, Yin-Lin Li1
1Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, P. R. China.
这项研究介绍了第一个催化不对称 (3+2) 循环添加,用于制造富含胺和四氨酸的环. 在这些具有挑战性的有机合成反应中,优化的性配体能够实现高产量和选择性.
科学领域:
- 有机化学
- 不对称的催化
- 合成方法
背景情况:
- 不对称的循环添加对于合成富含的循环化合物至关重要.
- 由于它们的热性禁止,使用 heteroallyl cations 的 hetero (3+2) 循环添加是罕见的和具有挑战性的.
- 之前没有报告产生丰富异环的不对称版本.
研究的目的:
- 开发第一个触媒不对称 (3+2) 循环添加反应,其中涉及电友-异二中间体.
- 合成高度替代或化的pyrrolidine和 tetrahydrofuran 环,具有高度的立体控制.
主要方法:
- 使用的电爱-异中间体 (Pd-OTMM或Pd-NTMM).
- 使用循环和非循环的1,3-二烯作为反应伙伴.
- 工程化硫胺 (Sadphos) 类型联体,特别是PC-Phos,具有二甲基-丁和/或3,5-二基.
主要成果:
- 实现了第一个用1,3-二烯的-异二循环添加.
- 提供高度替代的或化的pyrrolidine和tetrahydrofuran环,产量很高.
- 通过连接体工程表现出优异的区域性,异构性和反抗选择性.
结论:
- 通过- 异子成功建立了一种新型不对称的循环添加途径.
- 体设计,特别是PC-Phos变体,对于实现高催化性能和反选择性至关重要.
- 这种方法提供了一个强大的新工具,用于构建丰富的异环化合物.
更多相关视频
07:06A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
19:58Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
相关概念视频
Cycloaddition Reactions: MO Requirements for Thermal Activation
Cycloaddition Reactions: Overview
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Aldehydes and Ketones to Alkenes: Wittig Reaction Mechanism
The reaction begins with the nucleophilic addition between a phosphorus ylide and the carbonyl compound. Due to its carbanionic character, phosphorus ylide acts as a strong nucleophile and attacks the electrophilic carbonyl group. This generates a charge-separated dipolar intermediate called betaine. The negatively charged oxygen atom and...
![Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F51444.jpg&w=3840&q=50)