Microcrystalline Zinc Coordination Polymers as Single-site Heterogeneous Catalysts for the Selective Synthesis of Mono-oxazolines from Amino Alcohol and Dinitriles.
In our effort to develop coordination polymers (CPs)-based single-site catalysts for the selective synthesis of mono-oxazolines, two Zn-based CPs, [{Zn6 (idbt)4 (phen)4 } ⋅3 H2 O]n (1) and [{Zn3 (idbt)2 (H2 O)4 }⋅2 H2 O]n (2) (H3 idbt= 5,5'-(1H-imidazole-4,5-diyl)-bis-(2H-tetrazole), phen=1,10-phenanthroline) have been synthesized. They exhibit two-dimensional structure and contain isolated and accessible catalytically active sites, mimicking the site isolation of many catalytic enzymes. Micro CPs 1 and 2 are obtained by using surfactant-mediated hydrothermal methods, and an investigation is conducted to explore how different surfactants affect their morphologies and particle sizes. Furthermore, micro 1 and 2 have shown to be effective heterogeneous catalysts for the reaction of amino alcohols and aromatic dinitriles, and exerted a significant influence on the selectivity of the catalytic reactions, yielding mono-oxazolines as the major reaction product.