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

The tridentate ligands S(CH(2)CH(2)NHPiPr(2))(2) and S(CH(2)CH(2)OPiPr(2))(2) undergo C-S oxidative addition to give (SCH(2)CH(2)EPiPr(2))-Ni(CH(2)CH(2)EPiPr(2)) (E = NH (2), 0 (4)). The corresponding reaction of the aminophosphine ligand HN(CH(2)CH(2)NFIPiPr(2))(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(CH(2)CH(2)NHPiPr(2))(2)NiR]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.