尿素三酸盐混合催化剂,用于碳-碳键形成反应,其离子增强的反选择性 (enantioselectivity)
Li Liu1, Xingchen Dong1, Weijun Qin1
1Key Laboratory of Applied Surface and Colloid Chemistry, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China.
Journal of inorganic biochemistry
|October 3, 2024
概括
研究人员使用金属介导基对开发了可调节的核酸混合催化剂. 引入 (II) 离子在不对称反应中显著增强了酶选择性,为催化剂设计提供了新的策略.
科学领域:
- 协调化学 协调化学
- 催化剂是一种催化剂.
- 生物分子工程 生物分子工程
背景情况:
- 基因混合催化剂将活性金属嵌入到DNA支架中,以进行水性酶选择性转换.
- 核酸混合催化剂提供更简单的组件和固有的性,但缺乏结构性调整性.
- 限定的可调性阻碍了基于DNA的不对称催化剂的设计和应用.
研究的目的:
- 开发一种可调节的核酸混合催化剂策略,使用金属介导基对.
- 研究 (II) 离子在以核酸为基础的不对称反应中对抗选择性的作用.
- 阐明增强性性诱导的结构基础.
主要方法:
- 在核酸混合催化剂中构建乌拉-(II) - 乌拉 (U-Hg2+-U) 基对.
- 使用乌拉三酸盐 (UTP) 与Cu2+对Hg2+的催化活性和酶选择性的比较分析.
- 使用紫外线可见,圆形二重化和核磁共振进行光谱表征.
主要成果:
- 与UTP·Cu2+相比,U-Hg2+-U基对显著增强了酶选择性.
- 通过Hg2+,实现了Diels-Alder反应的38%的反体过量 (ee) 和迈克尔反应的22% ee的增加.
- 证明Hg2+调取决于核酸类型,金属度,辅因子,添加剂和反应条件.
结论:
- 金属介导的基对,特别是U-Hg2+-U,为核酸混合催化剂提供了可调节的策略.
- 形成U-Hg2+-U对和交叉连接的UTP-Hg2+-UTP/Cu2+组件是性增强的基础.
- 这种方法可以合理设计基于寡核酸的有力催化剂,用于各种反选择性反应.
更多相关视频
相关概念视频
Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
Oxymercuration-Reduction of Alkenes
Oxymercuration–reduction of alkenes is one of the major reactions converting alkenes to alcohols. It involves the hydration of alkenes with mercuric acetate in a mixture of tetrahydrofuran and water, forming an organomercury adduct. This is followed by a demercuration step in which the adduct is reduced to an alcohol using sodium borohydride.
Regioselectivity and Stereochemistry of Hydroboration
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 stereochemistry.
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 stereochemistry.
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
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...
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...
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...
![Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F51444.jpg&w=3840&q=50)

![[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)