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

Abstract

A range of thermomorphic polyethylene‐supported organocatalysts is prepared from N‐alkyl imidazoles and polyethylene iodide (PEI) with good yields (85–92%) and high funtionality (98–99%). The catalytic activity of these species is studied for the ring opening of epoxidized methyl oleate with CO2 to give the corresponding cyclic carbonate. The reaction is carried out at 100 °C to fully exploit the thermomorphic behavior of the organocatalysts. The optimized conditions (neat, 100 °C, and 20 bar of CO2) are applied to a range of epoxidized fatty acids, including an epoxidized rapeseed oil, to give the corresponding carbonates with good yields (75–96%). The catalyst recycling is also studied, and no significant loss of activity is observed after ten runs. The fatty carbonates are important intermediates for the preparation of non‐isocyanate polyurethanes (NIPUs).

Recent progress in the catalytic transformation of carbon dioxide into biosourced organic carbonates

“…338 A different and promising approach to the development of recoverable and reusable catalysts for the carbonation of epoxidized fatty acids was recently proposed by Duguet et al by using a thermomorphic polyethylene-supported catalyst. 339 In this latter example, the polymeric catalyst is soluble in the reaction mixture (T = 100°C) but insoluble in the product at room temperature. Therefore, it can essentially be recovered by filtration and its recyclability for the carbonation of epoxidized methyl oleate was indeed demonstrated.…”

Utilization of CO2-Available Organocatalysts for Reactions with Industrially Important Epoxides

“…Based on this idea, Akhdar et al successfully tested the carbonation of internal epoxide produced via the epoxidation of methyl oleate [61][62][63]. The catalysts were prepared by means of the alkylation of N-alkylimidazoles with oligoethylene iodide and modified by ion-exchange to the corresponding bromide.…”

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.…”