Synthesis of a First-Row Transition Metal Parent Amido Complex and Carbon Monoxide Insertion into the Amide N−H Bond

The parent amido iron complex (dmpe)2Fe(H)(NH2) (dmpe = 1,2-bis(dimethylphosphino)ethane), the first such first-row transition metal complex, has been synthesized and characterized spectroscopically and crystallographically. This complex has been found to insert carbon monoxide into the amide N−H bond (rather than the M−N bond) to give trans-(dmpe)2Fe(H)(NHCHO). The mechanism of this transformation has been studied and is believed to occur through an unusual mechanism in which CO behaves as an apparent electrophile.