Copper supported on N‐heterocyclic carbene‐functionalized porous organic polymer for efficient oxidative carbonylation of methanol

Abstract

A new heterogeneous catalyst for the oxidative carbonylation of methanol to dimethyl carbonate based on copper coordinated in N‐heterocyclic carbene‐functionalized porous organic polymer (Cu@PQP‐NHC) was presented. The solid catalyst that featured relatively large surface area, hierarchical pore structure, and excellent swelling property, was prepared via a facile copolymerization reaction of tetra‐vinylphosphonium salt and bis‐vinylimidazolium salt, followed by successful immobilization of CuCl. Accordingly, the resulting Cu@PQP‐NHC showed excellent catalytic performance for the oxidative carbonylation of methanol. A 10 mmol/l of Cu usage was sufficient for 9.3% conversion of methanol with a high TOF number of 57 h−1. Importantly, the catalyst was easily recovered by simple centrifugation, and could be reused up to 10 consecutive recycles without obvious loss of its initial activity. Also, the solid catalyst showed negligible Cu leaching during the recycling, and 99% Cu species was still retained after reusing 10 times. The results in this study highlights the advantages of porous organic polymer supported NHC‐Cu catalyst as a highly active and stable heterogeneous catalyst, providing a promising route for the synthesis of dimethyl carbonate.

New poly-imidazolium–triazole particles by CuAAC cross-linking of calix[4]arene bis-azide/alkyne amphiphiles – a prospective support for Pd in the Mizoroki–Heck reaction

“…Such heterogeneous catalysts have several advantages, the main one is the easy recovery and fast recycling of catalysts by ltration with the same activity as of homogeneous catalytic systems and their high surface area. [8][9][10] For the synthesis of such catalysts, the necessary anchor groups are introduced into the metal complex or NHCligand for immobilization on a organic/inorganic support (Scheme 1a). 11,12 An alternative approach is to include NHC fragments into the main polymer chain, which acquires both the function of the carrier and ligand (Scheme 1b).…”