Metal-organic framework based on copper(I) sulfate and 4,4′-bipyridine catalyzes the cyclopropanation of styrene

The hydrothermal synthesis of a new metal-organic framework (MOF) formulated as Cu2(4,4′-bpy)2SO4·6(H2O), [abbreviation: (1); bpy or 4,4′-bpy=4,4′-bipyridine; SO42−=sulfate group] has been reported. The structure of this MOF consists of Cu+ nodes connected via 4,4′-bpy to form infinite chains, with two neighboring chains further bridged on the nodes by SO42−, resulting in a 1-D double chain network. Guest water molecules reside in between the chains and are hydrogen-bonded to the O and S atoms from the nearest sulfate groups, leading to the formation of a 3-D supramolecular framework. This MOF is good heterogeneous catalyst for the cyclopropanation of styrene, with high trans cyclopropane diastereoselectivity and was recycled and reused for three consecutive cycles without a significant loss of catalytic activity.

Graphical AbstractA new MOF structure built up of 4,4′-bipyridine, sulphate and Cu(I), is an active heterogeneous catalyst for cyclopropanation of styrene with ethyldiazoacetate.Figure optionsDownload as PowerPoint slideHighlights
► The synthesis is different from solvothermal synthesis for other Cu(I) compounds.
► The compound and the structure are new.
► H bonds form infinite planes among water molecules and sulphate species.
► H bonding interaction makes the structure into a 3D supramolecular framework.
► Active catalytic property as heterogeneous catalyst for cyclopropanation of styrene.