A Ferrous Center as Reaction Site for Hydration of a Nitrile Group into a Carboxamide in Mild Conditions

Mild conversion of the nitrile substituent into an amide functional group is observed upon coordination of CNTPA [CNTPA = (6-cyano 2-pyridylmethyl)bis(2-pyridylmethyle)amine] to FeCl 2 followed by reaction with water. The crystal structure of CNTPAFeCl 2 is reported and reveals that the nitrile group does not coordinate but is activated in the vicinity of the ferrous center. Upon treatment with water under anaerobic conditions, CNTPAFeCl 2 converts into H 2 NCOTPAFeCl 2, [H 2 NCOTPA = (6-carboxamido 2-pyridylmethyl)bis(2-pyridylmethyle)amine], the X-ray crystal structure of which is reported. The new ligand H 2 NCOTPA can easily be obtained upon decomplexation.