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

Four nitrile ligated aluminum-based Lewis acids PhCNAl(OC(CF3)2PhCH3)3 (1), CH3CNAl(OC(CF3)2PhCH3)3 (2), PhCNAl(OC(CF3)2Ph)3 (3), CH3CNAl(OC(CF3)2Ph)3 (4) 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 4 h. Compound 1, being the best catalyst, yields 70% product within 10 min.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (83 K)Download as PowerPoint slideResearch highlights▶ Aluminum-based Lewis acids catalyze epoxide ring opening with amines. ▶ The Al catalysts are more efficient than borane analogues. ▶ The shape and basicity of the amine influence the product yield.