基于SET促进的光环化过程制备循环仿真物的合成策略
Ung Chan Yoon1, Ying Xue Jin, Sun Wha Oh
1Department of Chemistry, College of Natural Sciences, Pusan National University, Pusan 609-735, Korea.
Journal of the American Chemical Society
|August 28, 2003
概括
一种新方法使用SET促进的光环化合成循环类同类物. 这种方法提供了一种稳定有效的方法来创建这些复杂的分子,N-基替代增强稳定性.
科学领域:
- 有机化学 有机化学
- 类化学 类化学
- 摄影化学的使用.
背景情况:
- 循环在药物化学中很重要.
- 现有的合成方法可能很复杂,产量也很低.
研究的目的:
- 开发一种新高效的方法来合成循环类同类物.
- 调查影响光环化反应和产生的循环的稳定性的因素.
主要方法:
- 合成含有N终端胺和C终端α-胺基或α-胺碳酸盐群的基质.
- 在辐射下由单电子转移 (SET) 促进的光环化反应.
- 分析反应产量,化学效率和N-基替代的影响.
主要成果:
- 在适度到良好的产量中成功合成循环类相应物.
- 反应效率在很大程度上独立于链长度和碎片化途径 (脱化与脱碳化).
- 在胺基残留物上的N-基替代显著提高了循环产品的稳定性.
结论:
- 通过SET促进的光环化为循环类类似物提供了可行的途径.
- 该方法在链长度和碎片化机制方面是可靠的.
- N-基替代是增强合成循环的稳定性的关键策略.
相关概念视频
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
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
Olefin Metathesis Polymerization: Overview
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...

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