A Thermomorphic Polyethylene‐Supported Imidazolium Salt for the Fixation of CO₂ into Cyclic Carbonates

Abstract

An imidazolium catalyst supported on thermomorphic polyethylene (PE) was prepared from 1methylimidazole and polyethylene iodide (PEÀ I). The catalyst was characterized by 1 H and 13 C NMR, SEC and MALDI-ToF mass spectrometry. Its catalytic activity was evaluated in the ring-opening of epoxides with carbon dioxide to give cyclic carbonates under solvent-free conditions. The catalyst proved to be active at low catalyst loading (down to 0.1 mol%) and allows the reaction to occur at low CO 2 pressure (1-5 bar) and moderate temperature (100°C). A range of terminal and internal epoxides was converted to the corresponding cyclic carbonates with high yields and selectivities. The recyclability of the catalyst was studied and no significant loss of activity was observed after 5 runs.

Organocatalytic Synthesis of Substituted Vinylene Carbonates

“…Recovery and reuse of the catalyst might be the next step for an even improved method. Indeed, in this context, we have recently developed thermomorphic polyethylene‐supported organocatalysts for the preparation of saturated cyclic carbonates by CO 2 insertion into epoxides, [39] including vegetable oil derivatives [40] . The thermomorphic behavior of the polyethylene support allows the catalyst to exhibit similar reactivity to a homogeneous system while being fully recyclable.…”

Thermomorphic Polyethylene‐Supported Organocatalysts for the Valorization of Vegetable Oils and CO2

“…The catalyst screening was first carried out using cis ‐epoxidized methyl oleate 8 as a model substrate and CO 2 to form the corresponding cyclic carbonate 9 ( Table 2 ). Based on our previous results for the preparation of cyclic carbonates from internal epoxides and CO 2 , [ 48 ] the reactions were performed in solvent‐free conditions at 100 °C, under 20 bar of CO 2 for 20 h using 4 mol% of the catalyst.…”

“…Even better, in our case, the supported organocatalyst is more active than its nonsupported version, as already shown in our previous study. [ 48 ] Finally, the reaction was also performed with TBAB for further comparison. In that case, the conversion reached 96% and carbonate 9 was obtained with 93% yield (Table 3, entry 7).…”

“…In this context, we have recently reported the use of an organocatalyst supported on thermomorphic polyethylene (PE) [ 47 ] for the formation of cyclic carbonates from epoxides and CO 2 . [ 48 ] The benefit of such supported organocatalysts lies in the fact that they are homogeneous at high temperature and heterogeneous at room temperature. Therefore, they can offer both a high catalytic activity and a good recyclability.…”

Organocatalytic synthesis of vinylene carbonates

“…Recovery and reuse of the catalyst might be the next step for an even improved method. Indeed, in this context, we have recently developed thermomorphic polyethylene-supported organocatalysts for the preparation of saturated cyclic carbonates by CO2 insertion into epoxides, 31 including vegetable oil derivatives. 32 The thermomorphic behavior of the polyethylene support allows the catalyst to exhibit similar reactivity to a homogeneous systems while being fully recyclable.…”