MBA-cross-linked poly(N-vinyl-2-pyrrolidone)/ferric chloride macromolecular coordination complex as a novel and recyclable Lewis acid catalyst: Synthesis, characterization, and performance toward for regioselective ring-opening alcoholysis of epoxides

摘要

A novel macromolecular-metal coordination complex, MBA-cross-linked PNVP/FeCl3 material was fabricated by immobilization of water intolerant ferric chloride onto the porous cross-linked poly(N-vinyl-2-pyrrolidone) carrier beads as a macromolecular ligand or carrier which was prepared by suspension free-radical copolymerization of N-vinyl-2-pyrrolidone (NVP) and N,N '-methylene bis-acrylamide (MBA) as a crosslinking agent in water. The obtained PNVP/FeCl3 was characterized by UV/vis and FT-IR spectroscopies, TGA, FE-SEM, EDX, and ICP techniques. This heterogenized version of ferric chloride is a convenient and safe alternative to highly water intolerant ferric chloride. The catalytic performance of (PNVP/FeCl3) as an efficient and recyclable polymeric Lewis acid catalyst was appropriately probed in the regio-and stereoselective nucleophilic ring opening of various epoxides with various alcohols in excellent yields with TOF up to 182.48 h-1 without generating any waste. The activity data indicate that this heterogeneous catalyst is very active and could be easily recovered, and reused at least six times without appreciable loss of activity indicating its stability under experimental conditions.