Recyclable porous Ionic liquid catalysts from one-pot emulsion templating multicomponent polymerization

Porous poly(ionic liquid)s (PILs) combine the intrinsic features of ionic liquids (ILs) with properties of polymers and porous structures notably enlarged surface area, high ionic density, spatial structuration, and the tunability of their properties via counterions exchange. Over the years, they have become essential materials for many applications, i.e., gas separation, CO2 capture, energy storage, polymer electrolyte in Li-batteries, sensors and catalysis. Amongst them, porous poly(imidazolium)s (PIMs) are of great interest for cutting edge applications, especially for heterogenous catalysis. Their chemical composition catalyzes a wide range of reactions while their macrostructure allows easy recyclability without the need of advanced purification methods. However, structuring PIMs into porous materials is not trivial and requires multistep approaches based on the polymerization of preformed imidazolium monomers or by post-modification of porous organic networks. Therefore, the search for simpler and straightforward synthesis of porous PILs is highly relevant. In this respect, the emergence of multicomponent reactions (MCR), in which three or more compounds react and form a product containing essentially all atoms of the starting reagents, offers new opportunities. This communication aims at reporting a straightforward and atom economical approach for designing interconnected macroporous imidazolium-based networks. The latter combines for the first time the aqueous mediated Radziszewski MCR under high internal phase emulsion (HIPE) conditions. The catalytic activity and recyclability of these materials are illustrated for transesterification and decarboxylation reactions