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Phosphanylferrocenecarboxamide Ph2P-fc-CONHCH2CH2OH ( 1, fc = ferrocene-1,1′-diyl) and its newly synthesized congeners, Ph2P-fc-CONHCH(CH2OH)2 ( 2) and Ph2P-fc-CONHC(CH2OH)3 ( 3), were converted to a series of (η6-arene)ruthenium complexes [(η6-arene)RuCl2(L-κ P)] 5- 7, where arene is benzene, p-cymene, and hexamethylbenzene and L = 1- 3. All compounds were characterized by multinuclear NMR and IR spectroscopy, by mass spectrometry, and by elemental analysis. The molecular structures of 2, 3, 3O (a phosphane oxide resulting from the oxidation of 3), 5c·CH2Cl2, and 6c·Et2O were determined by single-crystal X-ray diffraction analysis. The ruthenium complexes were further evaluated as catalysts in the redox isomerization of allyl alcohols to carbonyl compounds. Complex [(η6- p-cymene)RuCl2( 1-κ P)] ( 5b) proved to be a particularly attractive catalyst, being both readily available and catalytically active. Substrates with unsubstituted double bonds were cleanly isomerized with this catalyst in 1,2-dichloroethane (0.5 mol-% Ru, 80 °C), whereas for those bearing substituents at the double bond (particularly in the position closer to the OH group) lower conversions and selectivities were achieved. A similar trend was noted when pure water was used as the solvent, except that the best results (complete conversion with 2 mol-% Ru) were seen for 1,3-diphenylallyl alcohol, the most hydrophobic substrate. [ABSTRACT FROM AUTHOR]

Abstract: Polar amido-phosphane ligands, viz 1-(diphenylphosphanyl)-1′-[N-(2-hydroxyethyl)carbamoyl]ferrocene (1) and 1-(diphenylphosphanyl)-1′-[N,N-bis(2-hydroxyethyl)carbamoyl]ferrocene (2) were synthesised from 1′-(diphenylphosphanyl)-1-ferrocenecarboxylic acid (Hdpf) by direct amide coupling or via Hdpf-pentafluorophenyl ester 3. Subsequent reactions of 1 and 2 with [PdCl2(cod)] (cod=η2:η2-cyclocta-1,5-diene) gave the respective bis(phosphane) complexes trans-[PdCl2L2] (4, L= 1; 5, L= 2). Depending on the solvent used in their subsequent crystallisation (ethanol or chloroform), these complexes were isolated in several defined solvated forms. The structure determination for free ligands and their solvated complexes (4·2EtOH, 4·6CHCl3, 5·2EtOH, and 5·4CHCl3) revealed the dominating role of hydrogen bonding in their crystal assemblies, the nature and complexity of the formed hydrogen-bonded arrays strongly varying with the ligand structure (one vs. two 2-hydroxethyl chains), their number in the discrete species (free ligands vs. the complexes), and also with the solvate. Catalytic tests performed with 4 and 5 in Suzuki–Miyaura cross-coupling reaction showed that both complexes form active catalysts for the coupling of aryl bromides with phenylboronic acid in common polar organic solvents, in water and in toluene–water biphasic mixture. Yet, complex 4 gave rise to hydrolytically more stable catalyst, which could be used five times without any detectable loss of activity in the toluene/water system. Complex 4 was also successfully applied to the synthesis of biaryl anti-inflammatory drugs and their analogues in pure water and in the toluene–water mixture. [Copyright &y& Elsevier]

• Platinum complexes with cyclometalated carbene and metallocene bisphosphine ligands were prepared. • The compounds were characterized by spectroscopic methods and cyclic voltammetry. • Structures of two representatives were determined by X-ray diffraction analysis. • DFT calculations were used to described the bonding situation in these componds. Four cycloplatinated complexes of the type [Pt(C^C*){M(η5-C 5 H 4 PPh 2) 2 -κ2 P,P '}][PF 6 ] n (M = Fe, n = 1; M = Co, n = 2), where C^C* is 2-(3-methylimidazol-2- ylidene-1-yl-κC2)phenyl-κC1 and similar cyclometalated ligands bearing an additional aromatic ring and phenyl substituents at the imidazol-2-ylidene unit, were prepared and structurally characterized by spectroscopic methods (NMR and ESI MS), elemental analysis, cyclic voltammetry and DFT calculations. Experimental structural parameters and DFT calculations consistently indicate differentiation of the Pt-bound phosphine groups due to unlike trans influence of the phenyl and carbene donor moieties at the cyclometalated ligand in these compounds [Display omitted] [ABSTRACT FROM AUTHOR]

A symmetrical flexible bis(phosphinoferrocene) derivative, viz. bis[1′-(diphenylphosphino)ferrocenyl]methane (1), was prepared and studied as a ligand in Pd(II) and Au(I) complexes. The reactions of 1 with [PdCl2(cod)] (cod = cycloocta-1,5-diene) and [Pd(μ-Cl)(LNC)]2 (LNC = [2-(dimethylamino-κN)methyl]phenyl-κC1) produced bis(phosphine) complex trans-[PdCl2(1-κ2P,P′)] (4), wherein the ligand spans trans positions in the square-planar coordination sphere of Pd(II) and the tetranuclear, P,P-bridged complex [(μ(P,P′)-1){PdCl(LNC)}2] (5), respectively. In reactions with the Au(I) precursors [AuCl(tht)] and [Au(tht)2][SbF6] (tht = tetrahydrothiophene), ligand 1 gave rise to tetranuclear Au2Fe2 complex [(μ(P,P′)-1)(AuCl)2] (6) and to symmetrical macrocyclic tetramer [Au4(μ(P,P′)-1)4][SbF6]4 (7). All compounds were characterized by spectroscopic methods. In addition, the structures of compound 1, its synthetic precursor bis[1′-(diphenylphosphino)ferrocenyl]methanone (3), and all aforementioned Pd(II) and Au(I) complexes were determined by single-crystal X-ray diffraction analysis (some in solvated form). [ABSTRACT FROM AUTHOR]

A new polar phosphinoferrocene ligand, viz. 1'-(diphenylphosphino)ferrocene-1-phosphonic acid (H 2 L), was prepared by hydrolysis of the corresponding phosphonate ethyl ester. However, the compound is relatively unstable, gradually decomposing upon prolonged storage, ultimately affording phosphine oxide H 2 L O. When the phosphine moiety was protected (e.g., in phosphine oxide H 2 L O and adduct H 2 L ·BH 3), no decomposition was observed. An alternative approach to prepare more stable H 2 L surrogates by converting the phosphonic acid into ammonium salts (dabcoH)(H L) and [(OHCH 2 CH 2) 2 NH 2 ](H L) (dabco = 1,4-diazabicyclo[2.2.2]octane) resulted in no significant stabilisation. H 2 L reacted with [PdCl 2 (cod)] (cod = cycloocta-1,5-diene), producing the bis(phosphine) complex, trans -[PdCl 2 (H 2 L -κ P) 2 ]. When mixed with Pd(II)-acetylacetonate (acac) complexes with ortho -metallated auxiliary ligands, [(LCY)Pd(acac)] (LCY = 2-[(dimethylamino-κ N)methyl]phenyl-κ C 1 and 2-[(methylthio-κ S)methyl]phenyl-κ C 1), H 2 L gave rise to bis-chelate complexes of the [(LCY)Pd(H L -κ2 O , P)] type. H 2 L , the ammonium salts featuring the H L − anion, and all Pd(II) complexes were structurally characterised by single-crystal X-ray diffraction analysis. Variations in phosphonate P-O bond lengths observed in the crystal structures were rationalised by DFT computations. Image 1 • A new polar phosphinoferrocene phosphonate ligand was prepared. • The compound was converted to its ammonium salts. • Pd(II) complexes with native and deprotonated ligand were synthesised. • Crystal structures of the salts and Pd(II) complexes were determined. [ABSTRACT FROM AUTHOR]

Abstract: {[Bis(2-(diphenylphosphino)ethyl)amino]carbonyl}ferrocene (3), a bulky ferrocenecarboxamido-diphosphine, was prepared in a good yield by the reaction of pentafluorophenyl ferrocenecarboxylate (2) with bis[2-(diphenylphosphino)ethyl]amine. The NMR data (1H VT NMR study in particular) indicated a limited molecular mobility of amide 3 that presumably results from a hindered rotation around the amide C–N bond leading to a non-equivalency of the substituents attached to the amide nitrogen. Compound 3 was further converted to the corresponding diphosphine disulfide 4 and reacted with [PtCl2(cod)] (cod = η2:η2-cycloocta-1,5-diene) to give the symmetric, ligand-bridged diplatinum complex [(μ-3)PtCl2]2 (5) having cis square-planar geometry around the Pt(II) centers. The molecular structures of 4 and 5 were determined by single-crystal X-ray diffraction analysis. [Copyright &y& Elsevier]

• Ferrocene-substituted diaminocarbenes were prepared from isocyanoferrocene. • Two types of compounds, mono- and biscarbenes, are obtained depending on stoichiometry. • The compounds form conformational isomers in solution. • In the solid state, N-H···Cl hydrogen bonds play a decisive role. Gold(I) acyclic diaminocarbene complexes of the [AuCl{C(NHFc)(NR 2)}] type (Fc = ferrocenyl) were conveniently synthesized by a one-pot procedure. In this method, 1 equiv. of isocyanoferrocene (FcNC) and an excess of primary or secondary amines R 2 NH (dimethylamine, morpholine, methylamine, cyclohexylamine, and p -toluidine) are sequentially added to [AuCl(SMe 2)] as a gold source in dichloromethane. The stepwise synthesis, in which [AuCl(FcNC)] is the isolated intermediate, worked equally well but generated lower overall yields due to compound loss during the two purification steps. The approach was further extended to synthesize the corresponding cationic biscarbene complexes [Au{C(NHFc)(NR 2)} 2 ]Cl simply by using 2 equiv. of FcNC during the "first" reaction step. The compounds form conformational isomers in solution that differ by the orientation of substituents at the carbene units. Based on DFT calculations, these isomers exhibit similar energies (energy difference ≤ 5 kcal mol–1). The crystal structures revealed symmetrical carbene units and the dominant role of the N-H⋅⋅⋅Cl interactions in the crystal assemblies in all cases, which also control the tendency for a particular conformation in the solid state. [Display omitted] [ABSTRACT FROM AUTHOR]