Synthesis of nitrile coordinated Lewis acids Al(OC(CF3)2R)3 and their application in catalytic epoxide ring-opening reactions

摘要

Four nitrile ligated aluminum-based Lewis acids PhCNAl(OC(CF3)2PhCH3)3, CH3CNAI(OC(CF3)2 PhCH3)3, PhCNAl(OC(CF3)2Ph)3 (3), CH3CNAl(OC(CF3)2Ph)3 were synthesized and characterized by nuclear magnetic resonance and infrared spectroscopy, as well as X-ray crystallography. The ring-opening reactions of epoxides with aromatic/aliphatic amines were efficiently catalyzed by compounds 1-4 as catalysts in a concentration of 1 mol% under solvent-free conditions at room temperature, affording 2-amino alcohols in high yields (up to 99%) within 4h. Compound 1, being the best catalyst, yields 70 % product within 10 min.