Disproportionation of PtPh(CH₂COMe)(cod) and Conproportionation of PtPh₂(cod) and Pt(CH₂COMe)₂(cod) via Intermolecular Phenyl Ligand Transfer

Abstract

PtI(Ph)(cod) (cod ) 1,5-cyclooctadiene) reacts with acetone in the presence of Ag 2 O to give a mixture of Pt(CH 2 COMe)(Ph)(cod) (1), PtPh 2 (cod) (2), and Pt(CH 2 COMe) 2 (cod) (3) in a molar ratio of 61:20:19. Complex 1, having the phenyl and acetonyl ligands, was isolated by recrystallization of the products and characterized by X-ray crystallography. The reaction of AgBF 4 with PtI(Ph)(cod) forms [PtPh(cod)(acetone-d 6 )]BF 4 and does not give a diarylplatinum complex. Thus, Ag 2 O, in the reaction of PtI(Ph)(cod) with acetone, promotes activation of both the Pt-I bond of PtI(Ph)(cod) and a C-H bond of acetone. Heating of 1 in acetone at 50 °C causes its partial disproportionation into 2 and 3 to give a mixture of the above three complexes. An equimolar mixture of 2 and 3 in acetone undergoes conproportionation into 1 at 50 °C to give a mixture of the complexes. The conproportionation is completed in 30 h to form the mixture with [1]:[2]:[3] ) 66:17:17, while the above disproportionation of 1 does not attain equilibrium even after 70 h. The disproportionation and conproportionation of these complexes are observed also in benzene at 50 °C.

Bimetallic Catalysis using Transition and Group 11 Metals: An Emerging Tool for CC Coupling and Other Reactions

“…Ligand disproportionation of a Pt complex with aryl and acetonyl ligands has been reported by Osakada et al to give diaryl-platinum and diacetonyl-platinum complexes, both in acetone and in benzene. [46] Recently, Sanford and co-workers studied, computational and experimentally, the influence of ancillary ligands on the ligand disproportionation of cis- L 2 ] intermediates, which eventually leads to undesired homocoupling products in the cross-coupling reactions (Scheme 21). [48][49][50] Lo Sterzo et al have reported a number of examples of palladium-catalyzed metal-carbon bond-formation with alkynyl stannanes (Scheme 22), [51][52][53][54] and have detected spectroscopically a pentacoordinated palladium intermediate that is suggested to be a model of the transition state proposed in the cyclic mechanism of the Stille reaction.…”

An unprecedented process involving normal and redox transmetallation reactions between Hg and Pt affording the unexpected K[Pt2{CH2C(O)Me}6(μ-Cl)3] complex: the key role of X-ray powder diffraction in unravelling its nature and structure

“…3 Most reported acetonyl complexes [Pt(II)]CH 2 C(O)Me have been obtained through methods that inevitably lead to species also containing phosphines, pyridine derivatives, Me or Ph ligands. 4,5 The only acetonyl platinum complex containing an easily exchangeable ligand is [Pt{CH 2 C(O)Me} 2 (COD)] (COD 5 1,5-cyclooctadiene), which has recently been reported in low yield. 5 We have reported the synthesis of [Pd{CH 2 C(O)Me}Cl] n , which allows preparation of acetonyl palladium complexes choosing freely any additional ligand.…”

“…4,5 The only acetonyl platinum complex containing an easily exchangeable ligand is [Pt{CH 2 C(O)Me} 2 (COD)] (COD 5 1,5-cyclooctadiene), which has recently been reported in low yield. 5 We have reported the synthesis of [Pd{CH 2 C(O)Me}Cl] n , which allows preparation of acetonyl palladium complexes choosing freely any additional ligand. 2 The same method that uses [Hg{CH 2 C(O)Me} 2 ] to transmetallate the acetonyl ligand, is here reported to give Pt(II) and Pt(IV) acetonyl chlorocomplexes.…”

Formation, Dynamic Behavior, and Chemical Transformation of Pt Complexes with a Rotaxane‐like Structure

“…Carboxylic acids react with [Pt(CH 2 COMe)(Ph)(cod)] ( 1 ; cod=1,5‐cyclooctadiene) to form carboxylate–platinum complexes 23. This reaction is employed as the end‐capping reaction of pseudorotaxanes whose axis molecule has a carboxy group as the terminal group.…”

“…1 ,23 [Pt(X)(Ph)(cod)] (X=Cl, I, Ph),34 {(DB24C8)( 2 ‐H)} + (PF 6 ) − ,24 (ArCH 2 NH 2 CH 2 Ar) + (PF 6 ) − (( 7 ‐H) + (PF 6 ) − : Ar=Ph, ( 12 ‐H) + (PF 6 ) − : Ar=4‐ t BuC 6 H 4 ),25, 26 and (py‐H) + (PF 6 ) −[35] were prepared according to the methods in the literature. Other chemicals were commercially available.…”