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New ligand precursors with different pendent alky chain length were obtained in a single step by reacting appropriate 1-alkyl-2-methyl-1 H -imidazoles with chloroacetone in THF at 80 °C overnight. Zwitterionic palladium complexes were prepared by reacting PdCl 2 with these new imidazole derivatives in DMF with the presence of pyridine and Cs 2 CO 3 as base at room temperature for 5 h. These new compounds were characterized by 1 H and 13 C{ 1 H} NMR spectroscopy, elemental analysis, and electrospray ionization mass spectrometry. They were effectively applied as recyclable catalysts for mediating Mizoroki–Heck reactions in ionic liquids. Transmission emission microscopy revealed that palladium nanoparticles were formed during the catalytic process. [ABSTRACT FROM AUTHOR]

Abstract: Reactions of ω-diphenylphosphinofunctionalized alkyl phenyl sulfides Ph2P(CH2) n SPh (n = 1, 1a; 2, 2a; 3, 3a), sulfoxides Ph2P(CH2) n S(O)Ph (n = 1, 1b; 2, 2b; 3, 3b) and sulfones Ph2P(CH2) n S(O)2Ph (n = 1, 1c; 2, 2c; 3, 3c) with dinuclear chlorido bridged rhodium(I) complexes [(RhL2)2(μ-Cl)2] (L2 = cycloocta-1.5-diene, cod, 4; bis(diphenylphosphino)ethane, dppe, 5) afforded mononuclear Rh(I) complexes of the type [RhCl{Ph2P(CH2) n S(O) x Ph-κP}(cod)] 1 [1] Here and in the following the letters a, b, and c in the numbering schemes refer to a sulfanyl (x = 0), sulfinyl (x = 1) and sulfonyl (x = 2) functionality, respectively. (n/x = 1/0, 6a; 1/1, 6b; 1/2, 6c; 2/0, 8a; 2/1, 8b; 2/2, 8c; 3/0, 10a; 3/1, 10b; 3/2, 10c) and [RhCl{Ph2P(CH2) n S(O) x Ph-κP}(dppe)] (n/x = 1/0, 7a; 1/1, 7b; 1/2, 7c; 2/0, 9a; 2/1, 9b; 2/2, 9c; 3/0, 11a; 3/1, 11b; 3/2, 11c) having the P^S(O) x ligands κP coordinated. Addition of Ag[BF4] to complexes 6–11 in CH2Cl2 led with precipitation of AgCl to cationic rhodium complexes of the type [Rh{Ph2P(CH2) n S(O) x Ph-κP,κS/O}L2][BF4] having bound the P^S(O) x ligands bidentately in a κP,κS (13a–18a, 15b–18b) or a κP,κO (13b, 14b, 13c–18c) coordination mode. Unexpectedly, the addition of Ag[BF4] to 6a in THF afforded the trinuclear cationic rhodium(I) complex [Rh3(μ-Cl)(μ-Ph2PCH2SPh-κP:κS)4][BF4]2·4THF (12·4THF) with a four-membered Rh3Cl ring as basic framework. Addition of sodium bis(trimethylsilyl)amide to complexes 6–11 led to a selective deprotonation of the carbon atom neighbored to the S(O) x group (α-C) yielding three different types of organorhodium complexes: a) Organorhodium intramolecular coordination compounds of the type [Rh{CH{S(O) x Ph}CH2CH2PPh2-κC,κP}L2] (22a–c, 23a–c), b) zwitterionic complexes [Rh{Ph2PCHS(O) x Ph-κP,κS/O}L2] having κP,κS (21a, 21b) and κP,κO (20b/c, 21c) coordinated anionic [Ph2PCHS(O) x Ph] ligands, and c) the dinuclear rhodium(I) complex [{Rh{μ-CH(SPh)PPh2-κC:κP}(cod)}2] (19). All complexes were fully characterized spectroscopically and complexes 15b, 15c, 12·4THF and 19·THF additionally by X-ray diffraction analysis. DFT calculations of zwitterionic complexes gave insight into the coordination mode of the [Ph2PCHS(O)Ph] ligand (κP,κS versus κP,κO). [Copyright &y& Elsevier]

The SPh functionalized vinyliminium complexes [Fe2{μ-η1:η3-Cγ(R′)=Cβ(SPh)Cα=N(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] [R = Xyl, R′ = Me, 2a; R = Me, R′ = Me, 2b; R = 4-C6H4OMe, R′ = Me, 2c; R = Xyl, R′ = CH2OH, 2d; R = Me, R′ = CH2OH, 2e; Xyl = 2,6-Me2C6H3] are generated in high yields by treatment of the corresponding vinyliminium complexes [Fe2{μ-η1:η3-Cγ(R′)=Cβ(H)CαN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (1a–e) with NaH in the presence of PhSSPh. Likewise, the diruthenium complex [Ru2{μ-η1:η3-Cγ(Me)=Cβ(SPh)Cα=N(Me)(Xyl)}(μ-CO)(CO)(Cp)2][SO3CF3] (2f) was obtained from the corresponding vinyliminium complex [Ru2{μ-η1:η3-Cγ(Me)=Cβ(H)Cα=N(Me)(Xyl)}(μ-CO)(CO)(Cp)2] (1f). The synthesis of 2c is accompanied by the formation, in comparable amounts, of the aminocarbyne complex [Fe2{μ-CN(Me)(4-C6H4OMe)}(SPh)(μ-CO)(CO)(Cp)2] (3).The molecular structures of 2d, 2e and 3 have been determined by X-ray diffraction studies. [Copyright &y& Elsevier]

The zwitterionic vinyliminium complex [Fe2{μ-η1:η3-C(R′)ᆖC(S)CᆖN(Me)(Xyl)}(μ-CO)(CO)(Cp)2] (2a) (R′ = p-Me-C6H4 (Tol), Xyl = 2,6-Me2C6H3) undergoes electrophilic addition at the S atom by HSO3CF3, MeSO3CF3, SiMe3Cl, BrCH2Ph, ICH2CHᆖCH2 affording the complexes [Fe2{μ-η1:η3-C(Tol)ᆖC(SX)CN(Me)(Xyl)}(μ-CO)(CO)(Cp)2][Y] (X = H, Y = SO3CF3, 4a; X = Me, Y = SO3CF3, 4b; X = SiMe3, Y = Cl, 4c; X = CH2Ph, Y = Br, 4d; X = CH2CHᆖCH2, Y = I, 4e). Compound 2a and the corresponding vinyliminium complexes 2b and 2c (R′ = CH2OH, 2b; R′ = Me, 2c) react also with etherated BF3 leading to the formation of the corresponding S-adducts [Fe2{μ-η1:η3-C(R′)ᆖC(SBF3)CᆖN(Me)(Xyl)}(μ-CO)(CO)(Cp)2] (R′ = Tol, 5a; R′ = CH2OH, 5b; R′ = Me, 5c). In analogous reactions, the zwitterionic vinyliminium complexes undergo S-metalation upon treatment with in situ generated [Fp]+[SO3CF3]− [Fp = Fe(CO)2(Cp)], leading to the formation of [Fe2{μ-η1:η3-C(R′)ᆖC(S–Fp)CᆖN(Me)(Xyl)}(μ-CO)(CO)(Cp)2][SO3CF3](R′ = CH2OH, 6a; R′ = Me, 6b; R′ = Bun, 6c). Similarly, zwitterionic vinyliminium containing Se in the place of S also undergo Se-electrophilic addition. Thus, the complexes [Fe2{μ-η1:η3-C(R′)ᆖC(SeX)CᆖN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R = X = Me, R′ = Tol, 7a; R = Xyl, R′ = Me, X = Fp+, 7b) are obtained upon treatment of the neutral zwitterionic precursors with MeSO3CF3 and [Fp][SO3CF3], respectively. Alkylation at the S or Se atom of the bridging ligand is also accomplished by CH2Cl2, used as solvent, although the reaction is slower compared to more efficient alkylating reagents. The complexes formed by this route are [Fe2{μ-η1:η3-C(R′)ᆖC(E-CH2Cl)CᆖN(Me)(R)}(μ-CO)(CO)(Cp)2][X] [E = S, R = Xyl, R′ = Tol, X = Cl, 8a; E = S, R = Xyl, R′ = Me, X = Cl, 8b; E = Se, R = R′ = Me, X = BPh4, 8c]. Finally, treatment of the zwitterionic vinyliminium complexes with I2 results in the oxidative coupling with formation of S–S (disulfide) or Se–Se (diselenide) bond. The reactions, performed in the presence of NaBPh4 afford the tetranuclear complexes [Fe2{μ-η1:η3-C(R′)ᆖC(E)CᆖN(Me)(R)}(μ-CO)(CO)(Cp)2]2[BPh4]2 [R = Xyl, R′ = CH2OH, E = S, 9a; R = Xyl, R′ = Me, E = S, 9b; R = Xyl, R′ = Bun, E = S, 9c; R = Xyl, R′ = Me, E = Se, 9d; R = Me, R′ = Bun, E = Se, 9e]. The molecular structures of 4a, 8c and 9e have been determined by X-ray diffraction studies. [Copyright &y& Elsevier]

Abstract: Formal [3+2] cycloaddition reactions between the bis-sulfonium zirconocene-ate dimer ▪1a and methylpropiolate, benzaldehyde and carbon disulfide afforded stable zwitterionic phosphonium zirconocene-ate complexes 2–4, respectively, with two orthocondensed five-membered heterocycles. X-ray crystal structure of 4 has been determined. Elemental chalcogens (S, Se, Te) gave rise also to a new variety of five-coordinate zirconium(IV) complexes (5–7) by a formal [3+1] cycloaddition reaction. In these bicyclic zirconates, sulfur is included in a five-membered ring while the second chalcogen is in a four-membered one. [Copyright &y& Elsevier]

[N-(2-Benzoylphenyl)benzamido-κ2N,O](η1-benzyl)(trimethylphosphine)Ni(II) (3) is prepared by the reaction of potassium N-(2-benzoylphenyl)benzamide and Ni(η3-CH2C6H5)Cl(PMe3). When 3 is treated with one equivalent of B(C6F5)3, one obtains a zwitterionic complex, [PhC(O)&z.sbnd;C6H4&z.sbnd;N&z.dbnd6;C(Ph)OB(C6F5)3-κ2N,O]Ni(η1-CH2C6H5)(PMe3) (4). When two equivalents of B(C6F5)3 is added, PMe3 is abstracted to give a η3-benzyl zwitterionic complex, [PhC(O)&z.sbnd;C6H4&z.sbnd;N&z.dbnd6;C(Ph)OB(C6F5)3-κ2N,O]Ni(η3-CH2C6H5) (5). Solid structures of 4 and 5 were determined by X-ray crystallography. When ethylene is added to 5, low molecular weight polyethylene is obtained. [Copyright &y& Elsevier]

Reaction of the chelating diamido complexes Zr(ABAn)(CH2Ph)2 [ABA1=N,N′-(SiMe3)2-2-amidobenzylamido, ABA2=N,N′-(SiMePh2)(SiMe3)-2-amidobenzylamido] with B(C6F5)3 leads to formation of the unstable zwitterionic adducts [Zr(ABAn)(CH2Ph)][(η6-PhCH2)B(C6F5)3] 1 (n=1) and 2 (n=2), as shown by low temperature NMR experiments that, moreover, enabled an insight into the molecular structure of these compounds in solution. Two intermediates of the decomposition of 1 and 2, that leads to complexes Zr(ABAn)(C6F5)2, were identified. [Copyright &y& Elsevier]