Bioinspired Iron-Catalyzed Dehydration of Aldoximes to Nitriles: A General N–O Redox-Cleavage Method

Abstract

Inspired by OxdA that operates biocatalytic aldoxime dehydration, we have developed an efficient iron catalyst, Cp*Fe­(1,2-Cy2PC6H4O) (1), which rapidly converts various aliphatic and aromatic aldoximes to nitriles with release of H2O at room temperature. The catalysis involves redox activation of the N–O bond by a 1e– transfer from the iron catalyst to the oxime. Such redox-mediated N–O cleavage was demonstrated by the isolation of a ferrous iminato intermediate from the reaction of the ketoxime substrate. This iron-catalyzed acceptorless dehydration approach represents a general method for the preparation of nitriles, and it also delivers salicylonitriles by catalyzing the Kemp elimination reaction.