Synthesis of Palladium Sulfonium Ylides and the Structures of trans-[PdCl(CH₂SR₂)(PBu^t₂H)₂]X (X = CF₃SO₃, SR₂ = Tetrahydrothiophene; X = PF₆, R = Et)

Abstract

By reacting trans-[PdCl(CH2Cl)(PBut 2H)2] with tetrahydrothiophene (THT) or diethyl sulfide in the presence of AgCF3SO3 or TlPF6, the cationic palladium sulfur ylides trans-[PdCl(CH2SR2)(PBut 2H)2]X ((2)CF3SO3 SR2 = THT, X = CF3SO3; (2)PF6 SR2 = THT, X = PF6; (3)PF6 SR2 = SEt2, X = PF6) were isolated and characterized. The crystal and molecular structures of (2)CF3SO3 and (3)PF6 were solved by X-ray analyses. The related complex cis-[PdCl{CH2S(H)CH3}(PBut 2H)2]CF3SO3 was prepared by an independent route, i.e., by the oxidative addition of the C−Cl bond of Cl−CH2SCH3 to Pd(PBut 2H)3 to form trans-[PdCl(CH2SCH3)(PBut 2H)2], which was then protonated with triflic acid.

Zwitterionic Ammoniumalkenyl Ligands in Metal Cluster Complexes. Synthesis, Structures, and Transformations of Zwitterionic Trimethylammoniumalkenyl Ligands in Hexaruthenium Carbido Carbonyl Complexes

“…There are a number of examples in which these zwitterions are complexed to metal atoms, e.g., C and D . Almost all are coordinated exclusively through the carbon atom, and the negative charge is formally transferred to the metal atom. , There are also a variety of more extended zwitterionic hydrocarbylonium species. Most examples of these species contain the phosphonium grouping.…”

Ylide Ligands

“…This method is quite general and usually occurs in very mild reaction conditions. Platinum, rhodium, iron and palladium complexes (21)-(25) (Scheme 8) have been prepared, using phosphines [79][80][81][82][83], amines [84] or sulfides [85] as nucleophiles. Some of the most representative examples are shown in Scheme 8.…”

“…Therefore, it seems logical that the reaction of a metallic carbene with a nucleophile would give a metal bonded ylide and, in fact, this a quite useful method to prepare metallated ylides. Even more, in some cases coordinated ylides have been used as masked carbenes [85]. Complexes (26) (Scheme 9, M = Cr, W), which contain a pyridinium ylide, are conveniently prepared by reaction of the corresponding carbenes [(CO) 5 M=C(OEt)R] with 1,2-or 1,4-dihydropyridines.…”

“…The methylenic protons between the two phosphorus atoms of these chelating ligands, even coordinated, are acidic and, therefore, can be easily removed and replaced by other electrophilic substrates. Using this concept, Laguna et al have prepared a large series of mono-, di-and trinuclear complexes of general structure (85), mixing a central square-planar Au III center and peripheric Au I or Ag I metal centers [173][174][175]. In contrast with the numerous examples reported with stabilized ylides, very few representatives of non-stabilized ylides (86), shown in Scheme 24, appear in the literature [176][177][178].…”

Synthesis, Structures, and Transformations of Bridging and Terminally-Coordinated Trimethylammonioalkenyl Ligands in Zwitterionic Pentaruthenium Carbido Carbonyl Complexes

“…The best known examples of these are the phosphorus- and sulfur-ylides A and B that were first reported by Wittig in the 1950s . These and other ylides are valuable reagents in organic syntheses. , These ylides are well known to coordinate to metal atoms by using the negatively charged carbon atom which formally transfers its negative charge to the metal atom upon coordination, see C and D below, and the complex becomes a zwitterion. , …”