Selectivity in reactions of alkyl-aryl-transition-metal complexes with electrophiles

Abstract

Registry NO. tr~ns-[Ru(bpy)~(pyz)~](PF,),, 79733-75-8; trans-[ Ru( b p~) , ( p y )~] (ClO,),, 633 58-69-0; trans-[ Ru(bpy),-(CH3CN)(H2O)](Cl0,),, 79681-78-0; lrans-[Ru(bpy)*-(CH3CN)2](C104)2, 79732-91-5; trans-Ru(bpy),Cl,, 34795-02-3; trans-[ R~( M e~b p y ) , ( P P h , )~] (PF,),, 7968 1-80-4; trans-[ Ru-(Me2bpy)2(PPh2Me)2](PF6)2, 79681-82-6; trans-[Ru(Me,bpy),-(PPhMe,),] (PFs)2, 7968 1-84-8; tram-[Ru(bpy),(NO)(OH)] (PF6)2, 7968 1-86-0; ci~-[Ru(bpy)~(CH,CN),] (PF,),, 55 124-54-4; cis-[Ru-(Me2bpy),(PPh3)(C1)]PF6, 79681-88-2; trans-[Ru(bpy),(OH,),]-(ClO,),, 72203-26-0; Ru(bpy),CO,, 59460-48-9; cis-Ru(Me2bpy),C1,, The new methylarylmetal complexes cis-[AuMe2Ph(PPh3)], cis-[AuMe2(4-MeC6H4)(PPh,)], [PtMe(4-MeC6H,)(.CsH12)], cis-[PtMePh(PMePh,),], and ~is-[PtMe(4-Mec,H,)(PMe,Ph)~] have been prepared and characterized. In reactions with electrophilic reagents such as HC1, HgCl,, and [PtI,(PMe,Ph),], the complexes undergo selective cleavage of a methyl-metal bond (e.& cis-[PtMePh(PMePh,),]) or an aryl-metal bond (e&, cis-[AuMe,Ph(PPh,)], [PtMe(4-MeC6H4)(CEH,,)]).From the selectivity observed and from studies of relative rates of reaction, it is argued that the SE2 mechanism leads to selective aryl-metal bond cleavage and that a different mechanism, probably involving an oxidative-addition-reductiveelimination sequence, leads to selective methyl-metal bond cleavage.

Generation and Structural Characterization of a Gold(III) Alkene Complex

“…2.2 equiv) to a CD 2 Cl 2 solution of 1 at −78 °C followed by warming to −40 °C yielded the Au III dimethyl species [(tpyH)AuMe 2 (OTf)] ( 2 ) 39. Selective protonolysis of the AuC(sp 2 ) bond, as has been observed in other Au III complexes,40 is confirmed by the two inequivalent AuMe groups, the absence of methane, and the symmetry of the tolyl group. NOE interactions between the protons of one AuMe group and aromatic protons of tpyH suggest that tpyH is coordinated to Au as a monodentate ligand in 2 through the N atom.…”

Generation and Structural Characterization of a Gold(III) Alkene Complex

“…2.2 equiv) to a CD 2 Cl 2 solution of 1 at À78 8C followed by warming to À40 8C yielded the Au III dimethyl species [(tpyH)AuMe 2 -(OTf)] (2). [39] Selective protonolysis of the AuÀC(sp 2 ) bond, as has been observed in other Au III complexes, [40] is confirmed by the two inequivalent AuMe groups, the absence of methane, and the symmetry of the tolyl group. NOE interactions between the protons of one AuMe group and aromatic protons of tpyH suggest that tpyH is coordinated to Au as a monodentate ligand in 2 through the N atom.…”

Transmetalation of arylpalladium and platinum complexes. Mechanism and factors to control the reaction

“…Aryl ligand transfer between the Pt and Pd complexes was also reported. cisPtMe(C 6 H 4 Me-4)(L 2 ) (L 2 = cod, 2PMe 2 Ph) reacts with cis-PdCl 2 (PMe 2 Ph) 2 to form different products depending on the kind of the auxiliary ligand at the Pt center (Scheme 8) [27]. PtMe(C 6 H 4 Me-4)(cod) having cod ligand reacts with Pd complex to form PtCl(Me)(cod) via transfer of the chloro ligand from Pd to Pt.…”