New nano-Fe3O4-supported Lewis acidic ionic liquid as a highly effective and recyclable catalyst for the preparation of benzoxanthenes and pyrroles under solvent-free sonication

RSC Adv. 2018 Oct 18;8(62):35681-35688. doi: 10.1039/c8ra04893b. eCollection 2018 Oct 15.

Abstract

A novel magnetic nanomaterial-immobilized Lewis acidic ionic liquid was successfully synthesized by the covalent embedding of 3-(3-(trimethoxysilyl)propyl)-1H-imidazol-3-ium chlorozincate (ii) ionic liquid to the surface of Fe3O4 nanoparticles. The material was then characterized by FT-IR, SEM, TEM, TGA, ICP-OES, Raman, and EDS. Its performance as a new-generation Lewis acidic catalyst was also examined on the ultrasound-mediated synthesis of benzoxanthenes and pyrroles. Upon completion, the catalyst was simply recovered by an external magnet for multiple reuses without significant lessening of catalytic performance.