Department of Chemistry and Biochemistry, University of Colorado at Boulder , Boulder, Colorado 80309, United States.
Acc Chem Res. 2014 May 20;47(5):1575-86. doi: 10.1021/ar500037v. Epub 2014 Apr 16.
The current research in the field of dynamic covalent chemistry includes the study of dynamic covalent reactions, catalysts, and their applications. Unlike noncovalent interactions utilized in supramolecular chemistry, the formation/breakage of covalent bonding has slower kinetics and usually requires the aid of a catalyst. Catalytic systems that enable efficient thermodynamic equilibrium are thus essential. In this Account, we describe the development of efficient catalysts for alkyne metathesis, and discuss the application of dynamic covalent reactions (mainly imine, olefin, and alkyne metathesis) in the development of organic functional materials. Alkyne metathesis is an emerging dynamic covalent reaction that offers robust and linear acetylene linkages. By introducing a podand motif into the catalyst ligand design, we have developed a series of highly active and robust alkyne metathesis catalysts, which, for the first time, enabled the one-step covalent assembly of ethynylene-linked functional molecular cages. Imine chemistry and olefin metathesis are among the most well-established reversible reactions, and have also been our main synthetic tools. Various shape-persistent macrocycles and covalent organic polyhedrons have been efficiently constructed in one-step through dynamic imine chemistry and olefin metathesis. The geometrical features and solubilizing groups of the building blocks as well as the reaction kinetics have significant effect on the outcome of a covalent assembly process. More recently, we explored the orthogonality of imine and olefin metatheses, and successfully synthesized heterosequenced macrocycles and molecular cages through one-pot orthogonal dynamic covalent chemistry. In addition to discrete molecular architectures, functional polymeric materials can also be accessed through dynamic covalent reactions. Defect-free solution-processable conjugated polyaryleneethynylenes and polydiacetylenes have been prepared through alkyne metathesis polymerization. We prepared imine- or ethynylene-linked porous polymer networks, which exhibit permanent porosity with high specific surface areas. Our most recent contribution is the discovery of a recyclable polyimine material whose self-healing can be activated simply by heating or water treatment. The facile access to complex functional organic molecules through dynamic covalent chemistry has allowed us to explore their exciting applications in gas adsorption/separation, host-guest chemistry, and nanocomposite fabrication. It is clear that there are significant opportunities for improved dynamic covalent systems and their more widespread applications in materials science.
目前动态共价化学领域的研究包括动态共价反应、催化剂及其应用的研究。与超分子化学中利用的非共价相互作用不同，共价键的形成/断裂具有较慢的动力学，通常需要催化剂的帮助。因此，能够实现高效热力学平衡的催化体系是必不可少的。在本综述中，我们描述了用于炔烃复分解反应的高效催化剂的开发，并讨论了动态共价反应（主要是亚胺、烯烃和炔烃复分解反应）在有机功能材料开发中的应用。炔烃复分解是一种新兴的动态共价反应，提供了坚固且线性的乙炔键。通过在催化剂配体设计中引入荚状基序，我们开发了一系列高活性和坚固的炔烃复分解催化剂，这些催化剂首次实现了一步共价组装乙炔键合的功能分子笼。亚胺化学和烯烃复分解是最成熟的可逆反应之一，也是我们的主要合成工具。通过动态亚胺化学和烯烃复分解，可以在一步中有效地构建各种形状保持的大环和共价有机多面体。构建块的几何形状和增溶基团以及反应动力学对共价组装过程的结果有显著影响。最近，我们探索了亚胺和烯烃复分解的正交性，并通过一锅正交动态共价化学成功合成了杂序列大环和分子笼。除了离散的分子结构外，还可以通过动态共价反应获得功能聚合物材料。通过炔烃复分解聚合制备了无缺陷的可溶液加工的共轭聚芳基乙炔和聚二乙酰基。我们制备了亚胺或乙炔键合的多孔聚合物网络，具有高比表面积的永久孔隙率。我们最近的贡献是发现了一种可回收的聚亚胺材料，其自修复可以通过加热或水热处理简单地激活。通过动态共价化学轻松获得复杂的功能有机分子，使我们能够探索它们在气体吸附/分离、主客体化学和纳米复合材料制备中的令人兴奋的应用。显然，动态共价体系有很大的改进空间，它们在材料科学中的应用也会更加广泛。
