Synthesis, reactivity, and structural studies in trimethylpalladium(IV) chemistry, including PdIMe3(bpy) and [MMe3((pz)3CH)]+ (M = palladium, platinum)

Reactivity of Diaryliodine(III) Triflates toward Palladium(II) and Platinum(II): Reactions of C(sp2)−I Bonds to Form Arylmetal(IV) Complexes; Access to Dialkyl(aryl)metal(IV), 1,4-Benzenediyl-Bridged Platinum(IV), and Triphenylplatinum(IV) Species; and Structural Studies of Platinum(IV) Complexes

“…Although reactivity of Pd(II) species with [IPh 2 ][OTf] was detected, Pd(IV) species could not be isolated owing to very low stability, so that their characterization relied on comparison of spectra with reported palladium complexes prepared by other methods (PdMePh(bpy), 20 PdIMe 3 (bpy), 21 PdIMe 2 Ph(bpy), 22 Dimethyl(phenyl)metal(IV) Species. The reaction of PdMe 2 (bpy) with [IPh 2 ][OTf] in 1:1 mole ratio at -50°C gave complex spectra that were difficult to interpret, and only about half of the iodonium reagent was consumed.…”

“…However, the pendant/substituent iodine atoms also interact. Thus (I(14)‚‚‚O(12) (x, y-1, z) 3.088(3), I(24)‚‚‚ O(22) (x, y-1, z) 3.335(3) Å) linking the pairs into strings; interestingly, despite the seeming noncrystallographic symmetry/equivalence of the two sets of 'ion pairs', the latter interaction for the second pair is less clear-cut, albeit still resulting in string formation, the iodine interacting as well with associated fluorines (I(24)‚‚‚F (21,23), O(22) (x, y-1, z) 3.556(4), 3.746(3), Å). As might be expected, there are also numerous other 'contacts' from diverse atoms to the iodines at longer distances.…”

Carbon–hydrogen (C–H) bond activation at PdIV: a Frontier in C–H functionalization catalysis

“…This strongly coordinating tridentate ligand is well-known to stabilize octahedral Pd IV species relative to analogues with bidentate nitrogen donors like bipyridine. 19 Thus, it was anticipated that the Py 3 CH ligand would slow C–H activation and enable more detailed mechanistic investigations of this process. Indeed, the Pd IV aryl complex 26 proved stable at room temperature and could be fully characterized by 1D and 2D NMR, HRMS, and X-ray crystallography.…”

High Oxidation State Organopalladium(IV) Species: Applications to C–H Activation

“…[14,16] Monitoring the subsequent reductive elimination by 1 H NMR spectroscopy revealed a cationic species (intermediate 3) with all Pd-CH 3 bonds remaining intact suggesting that iodide dissociation preceded ethane generation and structure 4 was formed via a cationic pentacoordinate palladium (IV) intermediate before the re-coordination of iodide. [17,18] The use of bipyridyl ligands to stabilise palladium(IV) species was first demonstrated in this study, [13] and represented a significant advance in the area. Indeed, the bipyridyl motif has come to represent a key structural feature of the overwhelming majority of chemistry featuring palladium(IV) species.…”