Single-crystal to single-crystal cross-linking of an interpenetrating chiral metal-organic framework and implications in asymmetric catalysis.
Single-crystal to single-crystal cross-linking of an interpenetrating chiral metal-organic framework and implications in asymmetric catalysis.
复制标题
DOI：
10.1002/anie.201003377
复制
发表时间：
2010-10
影响因子：
--
通讯作者：
Liqing Ma;Chuande Wu;Marcela M. Wanderley;Wenbin Lin
中科院分区：
文献类型：
--
作者：
Liqing Ma;Chuande Wu;Marcela M. Wanderley;Wenbin Lin
金属有机骨架材料由于其独特的性质在过去的十年中受到了广泛的关注。[1]MOFs由于其极高的孔隙率而表现出特殊的气体吸收能力。[2]结合所需官能团的能力允许MOFs在各种应用中发挥作用，例如催化，[3]化学传感，[4]和药物递送。[5]特别是，MOFs代表理想的候选人作为非均相催化剂，同时赋予孔隙率和引入催化位点到MOFs。与其他催化剂多相化策略不同，MOF衍生的多相催化剂可以保持稳定的结晶，从而为详细的结构询问提供了独特的机会，因此描绘了MOF结构与其催化活性和选择性之间的关系。由于大多数不对称催化反应都是在温和的非质子溶剂中进行的，因此我们最近将精力集中在手性多孔MOFs的设计上。[6]为了使手性MOFs成为有用的不对称催化剂，它们必须具有大的纳米尺度的开放通道，以便于空间要求高的底物和产物的运输。我们最近合成了基于四羧酸桥连配体（BINOL）和铜桨轮二级结构单元（SBU）的等网格手性MOFs，并观察到Et2Zn对芳香醛加成的对映选择性对MOFs开通道尺寸的显著依赖性。[7]为了扩大这类手性四羧酸配体的应用范围，并进一步了解骨架结构与催化活性之间的关系，我们将这些配体与其他金属连接点或金属簇SBU组合使用。
Metal–organic frameworks (MOFs) have received extensive interest in the past decade because of their interesting properties.[1] MOFs exhibit exceptional gas-uptake capacity owing to their extreme porosity.[2] The ability to incorporate desired functional groups allows MOFs to perform in a variety of applications, such as catalysis,[3] chemical sensing,[4] and drug delivery.[5] In particular, MOFs represent ideal candidates as heterogeneous catalysts by simultaneously imparting porosity and introducing catalytic sites into MOFs. Unlike other catalyst heterogenization strategies, the MOF-derived heterogeneous catalysts can remain singlecrystalline, thus providing a unique opportunity for detailed structural interrogation and therefore delineating the relationships between the MOF structures and their catalytic activities and selectivities.Moderate hydrolytic and thermal stabilities of most MOFs limit the scope of reactions that can be heterogeneously catalyzed by MOFs. We have recently focused our efforts on the design of chiral porous MOFs for heterogeneous asymmetric catalysis as most asymmetric catalytic reactions are carried out under mild conditions in aprotic solvents.[6] In order for chiral MOFs to be useful asymmetric catalysts, they must possess large nanometer-scale open channels for the facile transport of sterically demanding substrates and products. We have recently synthesized isoreticular chiral MOFs based on tetracarboxylate bridging ligands derived from 1, 1’-bi-2-naphthol (BINOL) and copper paddle-wheel secondary building units (SBUs), and observed the remarkable dependence of the enantioselectivities of the addition of Et2Zn to aromatic aldehydes on the MOF openchannel sizes.[7] In order to expand the scope of applications of such chiral tetracarboxylate ligands, and to further understand the relationships between framework structures and catalytic activities, we have used these ligands in combination with other metal-connecting points or metal-cluster SBUs.