Phosphotungstic acid salt of N-methyl-2-pyrrolidone: A green catalyst for Prins reactions of styrenes in formalin

摘要

Introduction Prins condensation is the cyclization of olefins with aldehydes usually catalyzed by mineral acids or Lewis acids. Recently, by bonding Keggin-structured heteropolyanions with conventional ion liquid (IL) organic cations, we synthesized a family of organic heteropolyacid salts with high melting points (above 100 ℃), which acted as novel reusable solid catalysts for esterifactions. To widen above studies, in this study, another organic heteropolyacid salt is synthesized by using N-Methyl-2-pyrodidone (NMP), a cheaper acidic functional IL-forming organic cation, and the catalyst causes a green Prins cyclization.