C−H Activation and C−C Coupling of Arenes by Cationic Pt(II) Complexes
- 1 October 2002
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 124 (42) , 12550-12556
- https://doi.org/10.1021/ja020798h
Abstract
The synthesis and characterization of cationic platinum complexes of the type [(R2PC2H4PR2)PtMe(OEt2)]BArF (R = Cy, Et) are reported. These electrophilic platinum cations are found to react quantitatively with arenes (benzene, toluene) at room temperature by undergoing intermolecular C−H activation with concomitant C−C coupling to generate complexes of the type [{Pt(R2PC2H4PR2)}2(μ-η3:η3-biaryl)][BArF]2. The dianionic biaryl ligands in these compounds exhibit a rare μ-η3:η3-bis-allyl bonding mode and can be removed from the complex with stoichiometric oxidants to generate the free biaryl and [(R2PC2H4PR2)Pt(μ-X)]2[BArF]2 (R = Cy, Et; X = Cl, I). The cationic platinum complexes [(R2PC2H4PR2)PtMe(OEt2)]BArF (R = Cy, Et) are also quite reactive with water, forming the bridging hydroxide complexes [(R2PC2H4PR2)Pt(μ-OH)]2[BArF]2 (R = Cy, Et). A possible mechanism is proposed for the C−C coupling reaction based upon the structures of these bridging biphenyl complexes, which provides a new perspective for the related palladium-catalyzed oxidative coupling of arenes to form biaryls.Keywords
This publication has 61 references indexed in Scilit:
- Unexpected Selectivities in C−H Activations of Toluene andp-Xylene at Cationic Platinum(II) Diimine Complexes. New Mechanistic Insight into Product-Determining FactorsJournal of the American Chemical Society, 2001
- Cationic Arylpalladium Complexes with Chelating Diamine Ligands, [PdAr(N−N)(solv)]BF4(N−N=N,N,N‘,N‘-tetramethylethylenediamine, 2,2‘-bipyridine, 4,4‘-dimethyl-2,2‘-bipyridine). Preparation, Intermolecular Coupling of the Aryl Ligands, and Insertion of Alkyne and Allene into the Pd−C BondOrganometallics, 2001
- Synthesis of and Small Molecule Coordination to Highly Electrophilic Cationic Manganese(I) and Rhenium(I) Carbonyl Complexes with Tied-Back PhosphitesOrganometallics, 2000
- C−H Activation at Pt(II) To Form Stable Pt(IV) Alkyl HydridesJournal of the American Chemical Society, 1997
- C−H Activation at Cationic Platinum(II) CentersJournal of the American Chemical Society, 1997
- Mechanism of the reaction of trans-bis(diethylphenylphosphine)di-m-tolylpalladium(II) with methyl iodide affording m-xylene. Evidence for a reductive elimination process involving the intermolecular exchange of organic groupsOrganometallics, 1986
- Dinuclear reductive eliminationsOrganometallics, 1984
- The Insertion of Diene Hydrocarbons in a Transition Metal–Ligand BondRussian Chemical Reviews, 1979
- Oxidative Coupling of Aromatic Systems under the Influence of Transition Metal CompoundsRussian Chemical Reviews, 1978
- Palladium-catalyzed syntheses of aromatic coupling compoundsThe Journal of Organic Chemistry, 1973