García-García Pilar, Moreno José María, Díaz Urbano, Bruix Marta, Corma Avelino
Instituto de Tecnología Química, UPV-CSIC, Universidad Politécnica de Valencia, Avenida de los Naranjos s/n, E-46022 Valencia, Spain.
Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain.
Nat Commun. 2016 Feb 25;7:10835. doi: 10.1038/ncomms10835.
Coordination polymers and metal-organic frameworks are appealing as synthetic hosts for mediating chemical reactions. Here we report the preparation of a mesoscopic metal-organic structure based on single-layer assembly of aluminium chains and organic alkylaryl spacers. The material markedly accelerates condensation reactions in water in the absence of acid or base catalyst, as well as organocatalytic Michael-type reactions that also show superior enantioselectivity when comparing with the host-free transformation. The mesoscopic phase of the solid allows for easy diffusion of products and the catalytic solid is recycled and reused. Saturation transfer difference and two-dimensional (1)H nuclear Overhauser effect NOESY NMR spectroscopy show that non-covalent interactions are operative in these host-guest systems that account for substrate activation. The mesoscopic character of the host, its hydrophobicity and chemical stability in water, launch this material as a highly attractive supramolecular catalyst to facilitate (asymmetric) transformations under more environmentally friendly conditions.
配位聚合物和金属有机框架作为介导化学反应的合成主体具有吸引力。在此，我们报告了一种基于铝链和有机烷基芳基间隔体单层组装的介观金属有机结构的制备。该材料在无酸或碱催化剂的情况下能显著加速水中的缩合反应，以及有机催化的迈克尔型反应，与无主体转化相比，该反应还表现出优异的对映选择性。固体的介观相使产物易于扩散，催化固体可回收再利用。饱和转移差分和二维（1）H核Overhauser效应NOESY核磁共振光谱表明，非共价相互作用在这些主客体系统中起作用，这解释了底物的活化。主体的介观特性、其疏水性以及在水中的化学稳定性，使这种材料成为一种极具吸引力的超分子催化剂，能够在更环保的条件下促进（不对称）转化。
