Oxidative Addition Reactions of Bis-Aminophosphine and Bis-Phosphinite Nickel(0) Pincer Complexes

The tridentate ligands S­(CH2CH2NHPiPr2)2 and S­(CH2CH2OPiPr2)2 undergo C–S oxidative addition to give (SCH2CH2EPiPr2)­Ni­(CH2CH2EPiPr2) (E = NH (2), O (4)). The corresponding reaction of the aminophosphine ligand HN­(CH2CH2NHPiPr2)2 is reversible, affording access to a transient Ni(0) synthon that undergoes oxidative addition with HCl, MeI, or o-ClC6H4F to give the Ni­(II) complexes [HN­(CH2CH2NHPiPr2)2NiR]­X (R = H, X = Cl (7), PF6 (8); R = Me, X = I (9); R = o-C6H4F, X = Cl (10)). These observations are supported via computations.