Carbon−Oxygen Bond Formation at Metal(IV) Centers: Reactivity of Palladium(II) and Platinum(II) Complexes of the [2,6-(Dimethylaminomethyl)phenyl-N,C,N]-(Pincer) Ligand toward Iodomethane and Dibenzoyl Peroxide; Structural Studies of M(II) and M(IV) Complexes
Citations Over TimeTop 10% of 2004 papers
Abstract
The presence of the [2,6-(dimethylaminomethyl)phenyl-N,C,N]- (pincer) ligand (NCN) in platinum(II) complexes has been used to generate stable organoplatinum(IV) complexes that model possible intermediates and reactivity in metal-catalyzed C−O bond formation processes. The complexes M(O2CPh)(NCN) [M = Pd (1), Pt (2)] were obtained by metathesis reactions from the chloro analogues, and although 1 does not react with dibenzoyl peroxide, 2 does so to form Pt(O2CPh)3(NCN) (3) as a model intermediate for the acetoxylation of arenes by acetic acid in the presence of palladium(II) acetate and an oxidizing agent. The complex Pt(O2CPh)(NCN) (2) reacts with iodomethane in a complex manner to form PtI(NCN) (6) and cis-Pt(O2CPh)2Me(NCN) (7). Complex 7 decomposes to form Pt(O2CPh)(NCN) (2) and MeO2CPh, probably via benzoate dissociation followed by nucleophilic attack by the benzoate ion at the PtIV-Me carbon atom. The Pd(II) analogue Pd(O2CPh)(NCN) (1) reacts with MeI to give PdI(NCN) (8) and MeO2CPh, for which the potential intermediacy of Pd(IV) species could not confirmed by 1H NMR spectroscopy. The complex PtTol(NCN) (4) (Tol = 4-tolyl) reacts with (PhCO2)2 to form cis-Pt(O2CPh)2Tol(NCN) (5), but, unlike the PtIVMe analogue 7, the PtIVTol complex 5 does not undergo facile C−O bond formation. X-ray structural studies of the isostructural square-planar complexes M(O2CPh)(NCN) (1, 2) and of the octahedral Pt(IV) complexes as solvates 3·1/2Me2CO, 5·Me2CO, and 7·Me2CO·H2O are reported. Complexes 5 and 7 have cis-PtC2 and cis-Pt(O2CPh)2 configurations.
Related Papers
- → Photoinitiated Oxidative Addition of CF3I to Gold(I) and Facile Aryl-CF3 Reductive Elimination(2014)149 cited
- → Oxidative Addition, Transmetalation, and Reductive Elimination at a 2,2′-Bipyridyl-Ligated Gold Center(2018)125 cited
- → Theoretical study of Pd(0)-catalyzed carbohalogenation of alkenes: mechanism and origins of reactivities and selectivities in alkyl halide reductive elimination from Pd(ii) species(2012)101 cited
- → Oxidative addition in the coupling of alkylgold(I) with alkyl halides(1974)102 cited
- → Aryl-Halide versus Aryl−Aryl Reductive Elimination in Pt(IV)−Phosphine Complexes(2006)57 cited