区域选择性 [3 + 2]/[4 + 2] 取消α-Nitrosostyrenes与Triazines的取消
Chenghao Zhu1, Changhao Wu1, Wenbo Jiang1
1School of Pharmaceutical and Chemical Engineering & Institute for Advanced Studies, Taizhou University, 1139 Shifu Avenue, Taizhou, Zhejiang 318000, China.
The Journal of organic chemistry
|June 10, 2025
概括
这项研究引入了使用α-nitrosostyrenes和hexahydro-1,3,5-triazines的区域选择性取消反应,以创建新的五和六个成员的异环环. 催化剂和反应条件被优化,以实现高效的合成.
科学领域:
- 有机化学 有机化学
- 异环化学 异环化学
- 催化剂是一种催化剂.
背景情况:
- α-酸是有机合成中的多功能合成.
- 六-1,3,5-triazines 作为含的构建块. 六-1,3,5-triazines 作为含的构建块.
- 区域选择性取消反应对于构建复杂的异环基架至关重要.
研究的目的:
- 开发新的区域选择性 [3 + 2] 和 [4 + 2] 取消反应.
- 调查催化剂的使用,以控制α-nitrosostyrene注销中的区域选择性.
- 探索反应条件对无效路径和产量的影响.
主要方法:
- 在α-bromooximes的α-nitrosostyrenes的现场生成.
- 催化 [3 + 2] 无效反应.
- 优化反应条件 (溶剂,温度) 用于 [4 + 2] 取消.
- 密度函数理论 (DFT) 计算以研究反应机制和激活障碍.
主要成果:
- 成功的区域选择性 [3 + 2] 和 [4 + 2] 用六-1,3,5-triazines 取消α-nitrosostyrenes.
- 在温和条件下的中等产量中形成五和六个成员的异环环.
- 催化剂有效控制了 [3 + 2] 途径中的区域选择性.
- 1,4-二和温度是调节 [4 + 2] 途径的关键因素.
- DFT计算表明Rh催化 [3 + 2] 解消的激活障碍较低.
- 证明了由此产生的循环和氧化的合成转化.
结论:
- 开发了一种新的合成策略,用于获取各种异环.
- 强调催化在实现区域选择性方面的关键作用.
- 提供了对竞争取消途径的机制性见解.
- 通过进一步的转换,展示了合成的异环的实用性.
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
相关概念视频
02:35Regioselectivity of Electrophilic Additions-Peroxide Effect
8.9K
In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.
8.9K
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
14.7K
If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
14.7K
02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
8.7K
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
8.7K
02:36Regioselectivity and Stereochemistry of Hydroboration
8.4K
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
8.4K
01:30Nucleophilic Aromatic Substitution: Addition–Elimination (SNAr)
4.1K
Nucleophilic substitution in aromatic compounds is feasible in substrates bearing strong electron-withdrawing substituents positioned ortho or para to the leaving group. The reaction proceeds via two steps: the addition of the nucleophile and the elimination of the leaving group.
The reaction begins with an attack of the nucleophile on the carbon that holds the leaving group. This results in the delocalization of the π electrons over the ring carbons. The resonance interaction between...
The reaction begins with an attack of the nucleophile on the carbon that holds the leaving group. This results in the delocalization of the π electrons over the ring carbons. The resonance interaction between...
4.1K
01:25Radical Anti-Markovnikov Addition to Alkenes: Overview
3.6K
The addition of hydrogen bromide to alkenes in the presence of hydroperoxides or peroxides proceeds via an anti-Markovnikov pathway and yields alkyl bromides.
3.6K