走向分子束的路上:活性金属模板合成3rotaxane,其中两个轴通过一个环线线穿过一个环
Hei Man Cheng1, David A Leigh, Francesca Maffei
1The School of Chemistry, University of Edinburgh, The King's Buildings, West Mains Road, Edinburgh EH9 3JJ, United Kingdom.
Journal of the American Chemical Society
|July 5, 2011
概括
研究人员使用尼克尔-特皮里丁复合物制造了一种新型的双线 [3] 罗他森. 这一突破使复杂的rotaxane架构通过将多个轴线连接到一个宏观循环中,从而实现高效的合成.
科学领域:
- 超分子化学 超分子化学
- 有机合成 有机合成
- 协调化学 协调化学
背景情况:
- 罗塔克桑是机械互锁的分子,在纳米技术中具有潜在的应用.
- 合成复杂的rotaxane架构,特别是那些具有多个组件的架构,仍然具有挑战性.
- 金属模板合成为构建复杂的分子架构提供了一个强大的策略.
研究的目的:
- 开发一种高效的合成双线螺纹[3]rotaxanes的方法.
- 为了研究使用2.2':6',2′′-terpyridylmacrocycle-Ni复合物在模板复杂的轮素形成中.
- 通过宏观循环来展示一个可通用的方法,通过宏观循环来线索多个轴.
主要方法:
- 采用了一种活性金属模板策略,采用了2.2':6',2" - - 特皮里迪尔宏循环-Ni复合体.
- 进行了sp(3) - 碳对sp(3) - 碳同反应以形成罗他森结构.
- 采用X射线晶体学,用于对双线螺纹[3]rotaxane.的结构性特征.
主要成果:
- 成功合成了一种罕见的双线螺纹[3]rotaxane,产量高达51%.
- 通过X射线结晶学证实了独特的一个环-两个线程架构.
- 证明了罗塔xane结构对脱线的稳定性,即使具有大型宏循环.
结论:
- 开发的活跃模板方法有效地调解了多个基链的线程进入宏观循环.
- 这项工作为构建复杂的rotaxane架构提供了可通用的策略.
- 这些发现扩大了合成先进超分子结构的工具包.
相关概念视频
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...
Ziegler–Natta Chain-Growth Polymerization: Overview
Ziegler–Natta polymerization is another form of addition or chain‐growth polymerization used for synthesizing linear polymers over branched polymers. The catalyst used for polymerization is the Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, who developed it in 1953. This catalyst is an organometallic complex of titanium tetrachloride and triethyl aluminum, with the active form of the catalyst being an alkyl titanium compound. Using the Ziegler–Natta catalyst, high molecular...
Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Radical Chain-Growth Polymerization: Mechanism
The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this species into the...
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.


