异构体环烯表现出独特的生物对等反应性
David N Kamber1, Lidia A Nazarova, Yong Liang
1Departments of †Chemistry, ‡Molecular Biology & Biochemistry, and §Pharmaceutical Science, University of California , Irvine, California 92697, United States.
Journal of the American Chemical Society
|September 5, 2013
概括
研究人员使用修改后的环烯开发了两种新的生物对等反应. 这些反应可以一起使用,使复杂的生物系统中的多个生物分子能够同时标记.
科学领域:
- 生物化学 生物化学
- 化学生物学 化学生物学
- 有机化学 有机化学
背景情况:
- 生物对等化学对于理解生物分子功能至关重要.
- 现有的生物对等反应往往缺乏兼容性,阻碍了同时进行研究.
- 需要正交的化学工具来研究复杂的生物过程.
研究的目的:
- 为了识别和描述两个新的,同时可用的生物对角反应.
- 开发直角反应性环烯支架,用于同时标记生物分子.
- 为了实时监控多组分生物过程.
主要方法:
- 利用了四素和1,3-非替代环烯之间的反向电子需求迪尔斯-阿尔德反应.
- 采用了1,3-二极性环添加烯胺和3,3-异位的环烯.
- 设计的环烯衍生物因直角反应性而有单一甲基的差异.
主要成果:
- 证明了两个不同的生物对等反应的同时效用.
- 展示了功能独特的环二烯的成功应用.
- 建立了两个开发的化学系统之间的正交反应性.
结论:
- 开发的生物对等反应和支架是兼容的同时使用.
- 这些工具显著提高了在复杂环境中协同研究多个生物分子的能力.
- 这项工作为监测细胞和生物体中复杂的多元生物过程提供了基础.
相关概念视频
Cycloaddition Reactions: Overview
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
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.
Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
Cycloaddition Reactions: MO Requirements for Thermal Activation
Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.
Prochirality
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...


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