Direct synthesis of sulfonic group tethered mesoporous poly(ionic liquid) for catalyzing deoximation reactions

Exploring new strategy towards efficient solid acids is significant for acid reactions. In this work, sulfonic group tethered mesoporous ionic copolymer Poly(DVB-VMPS), a kind of mesoporous poly(ionic liquid), was directly synthesized through the free radical copolymerization of sulfonic ionic liquid (IL) monomer (1-vinyl-3-propane sulfonate imidazolium) and divinylbenzene (DVB). Poly(DVB-VMPS) was used as an efficient polycation for pairing heteropolyacid (HPA) to fabricate HPA-based solid acid through solidification process. The obtained 12-tungstophosphoric acid (H₃PW) derived hybrid Poly(DVB-VMPS)PW acted as a robust solid acid in the acid-catalyzed hydrolysis deoximation reaction. High yield, stable reusability and well substrate compatibility were achieved, rendering a remarkable heterogeneous recyclable catalyst for this reaction. Compared with previous post-sulfonate analogue, Poly(DVB-VMPS)PW exhibited not only improved activity but also enhanced stability, reflecting the specialty and advantage of this direct synthesis route.