Rhenium(VII) Oxo Complexes as Extremely Active Catalysts in the Dehydration of Primary Amides and Aldoximes to Nitriles

An economical and environmentally benign process for the preparation of nitriles by the dehydration of primary amides and aldoximes is catalyzed by rhenium(VII) oxo complexes such as perrhenic acid and trimethylsilylperrhenate (see scheme). The reaction proceeds at azeotropic reflux (with the removal of water) under essentially neutral conditions.