Syntheses and structures of 2-diphenylphosphinomethylenide-6-diphenylphosphinomethylenepyridine complexes of palladium(II) and platinum(II); crystal structures of [PtCl2-(CHPPH2)-6-(CH2PPh2)pyridine] and [Pd(COOMe)2-(CHPPh2)-6-(CH2PPh2)pyridine]
Coordination of Olefins and N-Donor Ligands at the Fragment [2,6-Bis((diphenylphosphino)methyl)pyridine]- palladium(II). Synthesis, Structure, and Amination of the New Dicationic Complexes [Pd(PNP)(CH<sub>2</sub>CHR)](BF<sub>4</sub>)<sub>2</sub> (R = H, Ph)
[Pd(PNP)(MeCN)](BF4)2 by NHMe2 at 0 °C. The complexes were characterized by 1H, 13C, and 31P NMR spectroscopy, and the molecular structure of the styrene complex was determined by X-ray diffraction analysis. The spectral and structural parameters of the complexes are discussed in comparison to those of the recently prepared Rh(I) analogues. Nucleophilic attack of secondary amines on the coordinated olefins gave
a result of which the addition products can also be obtained starting from the substituted compounds [Pd(PNP)(NuH)](BF4)2 and the appropriate olefin. Equilibrium constants for the addition and substitution reactions have been determined in a number of cases. Proton abstractionfrom [Pd(PNP)(CHRCHR′NuH)]2+ by NaHCO3 quantitatively drives the equilibrium to β-functionalized alkyl complexes of the general
Mechanistic Studies of a Palladium-Catalyzed Intramolecular Hydroamination of Unactivated Alkenes: Protonolysis of a Stable Palladium Alkyl Complex Is the Turnover-Limiting Step
作者:Brian M. Cochran、Forrest E. Michael
DOI:10.1021/ja0734997
日期:2008.3.1
conditions was obtained from observation of the protonolysis at low temperature. During the course of all catalytic reactions, the resting state of the catalyst was palladium alkyl complex 7, indicating that protonolysis of the Pd-C bond was the turnover-limiting step. Kinetic studies reveal an unusual inverse dependence of the reaction rate on the concentration of the aminoalkene substrate. This effect can
Syntheses and structures of 2-diphenylphosphinomethylenide-6-diphenylphosphinomethylenepyridine complexes of palladium(II) and platinum(II); crystal structures of [PtCl2-(CHPPH2)-6-(CH2PPh2)pyridine] and [Pd(COOMe)2-(CHPPh2)-6-(CH2PPh2)pyridine]
作者:Adriano Sacco、Giuseppe Vasapollo、Cosimo F. Nobile、Angela Piergiovanni、Maria A. Pellinghelli、Maurizio Lanfranchi