Facile N–H Bond Cleavage of Ammonia by an Iridium Complex Bearing a Noninnocent PNP-Pincer Type Phosphaalkene Ligand

A novel PNP-pincer type phosphaalkene complex of iridium bearing a dearomatized pyridine unit (3) has been prepared. Complex 3 rapidly reacts with ammonia at room temperature to afford a parent amido complex in high yield. DFT calculations indicate that the phosphaalkene unit with a strong π-accepting property effectively facilitates the N–H bond cleavage of ammonia via metal–ligand cooperation.