在富勒伦上进行离子催化
Javier López-Andarias1, Antonio Frontera2, Stefan Matile1
1School of Chemistry and Biochemistry, University of Geneva , Quai Ernest Ansermet 30, CH-1211 Geneva, Switzerland.
Journal of the American Chemical Society
|September 14, 2017
概括
这项研究探讨了用于催化的烯的离子-π相互作用. 三级氨基可以选择性地加快酸盐和迪尔斯-阿尔德反应,为碳全方位应用开辟新的途径.
科学领域:
- 超分子化学
- 催化剂
- 材料科学
背景情况:
- 在烯化学中,离子-π 相互作用尚未得到充分的研究.
- 富勒伦具有独特的电子性质 (交换相关性,局部的π孔) 用于催化.
- 三级氨基可以在烯表面功能化.
研究的目的:
- 在催化应用中研究-π相互作用的潜力.
- 探索三级胺定位对富勒烯催化活性的影响.
- 在有机反应中确定富勒烯基催化剂的选择性和效率.
主要方法:
- 计算模拟可以模拟相互作用并预测选择性.
- 三级氨基功能化的富勒伦的合成.
- 在酸盐添加和迪尔斯-阿尔德反应中对催化性能进行实验评估.
主要成果:
- 通过离子-π 相互作用稳定富勒的离子过渡状态.
- 不受欢迎的酸盐添加和外迪尔斯-阿尔德反应的酶选择性加速.
- 基于平面化和电荷移位的基因,证明了对态元体的区别.
- 与平面系统相比,在富勒烯上观察到较短的酸盐-π相互作用.
结论:
- 在富勒烯上的离子-π相互作用提供了独特的催化选择性.
- 功能化的富勒伦可以作为有效的反选择性催化剂.
- 这些发现扩大了离子-π 相互作用和烯在催化中的应用范围.
相关概念视频
Aromatic Hydrocarbon Anions: Structural Overview
4.0K
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous...
Due to the absence of continuous...
4.0K
π Molecular Orbitals of the Allyl Cation and Anion
5.7K
An allyl group is a three-carbon conjugated system where the sp³-hybridized allylic carbon is bonded to a CH=CH2 group via a single bond. Allyl anions can be obtained by treating propene with a strong base that can deprotonate methyl groups. Allyl cations are formed as intermediates during substitution reactions involving allylic halides. In both cases, the hybridization of the allylic carbon changes from sp3 to sp2, giving rise to a carbon chain with three sp2-hybridized carbons, each with...
5.7K
Catalysis
30.9K
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.
30.9K
Aromatic Hydrocarbon Cations: Structural Overview
4.0K
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
Removing one hydrogen from the intervening CH2 group...
4.0K
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
9.1K
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.
9.1K
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.9K
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...
3.9K


