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The combination of different donor moieties often results in unconventional coordination behavior. This contribution describes the synthesis of a new hybrid ligand, phosphanylferrocene amidine Ph2PfcN=CHNMe2 (1; fc=ferrocene‐1,1′‐diyl), and its coordination behavior toward the light platinum metals. Reacting compound 1 with [PdCl2(MeCN)2] produced the chelate complex [PdCl2(1‐κ2P,N)] and the bis (phosphane) complex trans‐[PdCl2(1‐κP)2], depending on the ligand‐to‐metal stoichiometry. Halide removal from [PdCl2(1‐κ2P,N)] with Na[BARF] afforded the chloride‐bridged dimer [Pd2(μ‐Cl)2(1‐κ2P,N)2][BARF]2, which was presumably in equilibrium with the mononuclear κ3‐complex [PdCl(1‐κ3Fe,P,N)][BARF] in solution (BARF=tetrakis [3,5‐bis(trifluoromethyl)phenyl]borate). The reactions of 1 with the isoelectronic precursors [(arene)MCl(μ‐Cl)]2 (M/arene=Ru(II)/p‐cymene, and Rh(III)/C5Me5) generated the respective bridge‐cleavage products [(arene)MCl2(1‐κP)], which transformed into the P,N‐chelate complexes [(arene)MCl(1‐κ2P,N)][BARF] when treated with Na[BARF] as a chloride scavenger. All this suggests preferential coordination the phosphane moiety to soft metal ions, while the coordination of the amidine moiety can be induced through changing the reaction stoichiometry or by generating a vacant coordination site at the metal ion. The compounds were characterized using a combination of standard spectroscopic methods (multinuclear NMR, IR, and ESI MS) and single‐crystal X‐ray crystallography, and compounds 1 and 3 were further studied by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

Introducing a ferrocene moiety into a molecule results in the incorporation of a metal center and a redox active moiety. This contribution describes the synthesis of FcN(CH2PPh2)2 (1; Fc=ferrocenyl), a ferrocene analog of the widely studied bis‐phosphane pincer ligands, RN(CH2PPh2)2. Compound 1 was studied as a ligand in complexes of Group 10 and 11 metal ions. The following compounds were synthesized and characterized using a combination of spectroscopic methods and single‐crystal X‐ray diffraction analysis: the square planar complexes [MX2(1‐κ2P,P')] (M/X=Ni/Cl, Pd/Cl, Pd/Br, Pd/I and Pt/Cl) and the tetrahedral complexes [M(1‐κ2P,P')2]X (M/X=Cu/PF6, Ag/SbF6 and Au/SbF6). Furthermore, a pair of open and cyclic digold(I) complexes containing bis‐phosphane 1 as a P,P‐bridging ligand, viz. [(μ(P,P')‐1)(AuCl)2] and [(μ(P,P')‐1)2Au2][SbF6]2, were isolated. Ligand 1, the corresponding phosphane selenide 1‐Se and all complexes (except for the poorly soluble [(μ(P,P')‐1)2Au2][SbF6] and unstable [Ag(1‐κ2P,P')2][SbF6]) were further analyzed by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

(Ferrocenylmethyl)phosphane (1) oxidation with hydrogen peroxide, elemental sulfur and grey selenium produced (ferrocenylmethyl)phosphane oxide 1O, sulfide 1S and selenide 1Se, respectively, as the first isolable primary phosphane chalcogenides lacking steric protection. At elevated temperatures, compound 1O disproportionated into 1 and (ferrocenylmethyl)phosphinic acid. In reactions with [(η6‐mes)RuCl2]2, 1O underwent tautomerization into a phosphane complex [(η6‐mes)RuCl2{FcCH2PH(OH)‐κP}], whereas 1S and 1Se lost their P‐bound chalcogen atoms, giving rise to the phosphane complex [(η6‐mes)RuCl2(FcCH2PH2‐κP)] (Fc=ferrocenyl, mes=mesitylene). No tautomerization was observed in the reaction of 1O with B(C6F5)3, which instead produced a Lewis pair FcCH2P(O)H2‐B(C6F5)3. Phosphane oxide 1O added to C=O bonds of aldehydes and ketones and even to cumulenes PhNCE (E=O and S). However, both PH hydrogens were only employed in the reactions with aldehydes and cyanates. [ABSTRACT FROM AUTHOR]

A series of cationic Pt(II) complexes with chelating bis‐carbene and P,P‐ or P,S‐ligands, viz. [(C^C)Pt(X^Y)][BF4]2 (2a–e), where C^C = methylenebis(3‐methyl‐1H‐imidazol‐1‐yl‐2‐ylidene, and X^Y = Ph2PCH2CH2PPh2 (dppe) (a), Ph2P(CH2)3PPh2 (dppp) (b), 1,2‐(Ph2P)2C6H4 (dppbz) (c), [Fe(η5‐C5H4PPh2)2] (dppf) (d), and Ph2PCH2CH2SPh (e), were synthesized and structurally characterized by NMR and MS spectroscopy and by single‐crystal X‐ray diffraction analysis. Furthermore, photophysical measurements showed that these compounds were non‐emissive at room temperature. However, when cooled to 77 K, compounds 2a, 2b and 2c showed weak luminescence in the near UV region with emission maxima in the 380–395 nm range. [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]

Two series of asymmetric ferrocene diphosphines, namely the dppf-type ligands R 2 PfcPPh 2 (protected as BH 3 adducts; fc = ferrocene-1,1′-diyl) and their semi-homologous counterparts R 2 PfcCH 2 PPh 2 (both in free and BH 3 -protected form), with diverse PR 2 groups (R = cyclohexyl, isopropyl and tert -butyl), were prepared and further converted into the respective phosphine selenides, R 2 P(Se)fcP(Se)Ph 2 and R 2 P(Se)fcCH 2 P(Se)Ph 2 , which were in turn used to evaluate the electronic properties of these diphosphines through 1 J SeP coupling constants. When reacted with [PdCl 2 (MeCN) 2 ] or [PdCl 2 (cod)] (cod = cycloocta-1,5-diene), the dppf-type ligands exclusively afforded the chelate complexes [PdCl 2 (R 2 PfcPPh 2 -κ 2 P , P ′)], whereas the more flexible, homologous ligands produced mixtures mainly containing the similar chelate complexes [PdCl 2 (R 2 PfcCH 2 PPh 2 -κ 2 P , P ′)] and the P , P ′-bridged dimers [PdCl 2 (μ(P,P′)-R 2 PfcCH 2 PPh 2 )]2. [ABSTRACT FROM AUTHOR]

[1′-(Diphenylphosphino)ferrocenyl]methylamine ( 1 ) reacts with Ph 2 PH/(CH 2 O) x or [Ph 2 P(CH 2 OH) 2 ]Cl to give mixtures of Ph 2 PfcCH 2 NHCH 2 PPh 2 and Ph 2 PfcCH 2 N(CH 2 PPh 2 ) 2 in which the triphosphine dominates (fc = ferrocene-1,1′-diyl). To avoid unwanted two-fold phosphinomethylation, the amine group in 1 was alkylated. As expected, the reaction of the N -methyl analogue Ph 2 PfcCH 2 NHMe ( 5 ), obtained by reductive methylation of the aldehyde Ph 2 PfcCHO, with [Ph 2 P(CH 2 OH) 2 ]Cl, only led to the diphosphine Ph 2 PfcCH 2 N(Me)CH 2 PPh 2 ( 6 ). The diphosphine was structurally characterized and further reacted with [PdCl 2 (MeCN) 2 ] and [PdCl(Me)(cod)] (cod = η 2 :η 2 -cycloocta-1,5-diene), affording the respective trans -chelate complexes [PdCl(X){Ph 2 PfcCH 2 N(Me)CH 2 PPh 2 -κ 2 P , P ′}] ( 7a : X = Cl; 7b : X = Me), which were also structurally authenticated by X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Two homologous ferrocene phosphanylcarboxylic acids, viz., 1'-[(diphenylphosphanyl)methyl]ferrocene-1-carboxylic acid (HL1) and [1'-(diphenylphosphanyl)ferrocenyl]acetic acid (HL2), were synthesized and studied as ligands in PdII complexes. The addition of these hybrid donors to [PdCL2(MeCN)2] led to the bis-phosphane complexes trans-[PdCL2(HL1-κP)2] and trans-[PdCL2(HL2-κP)2]. In contrast, the reactions of HL1 and HL2 with the PdII acetylacetonate (acac) complexes [(LYC)Pd(acac)], where LYC = 2-[(dimethylamino-κN)methyl]phenyl-κC1 (LNC) and 2-[(methylthio-κS)methyl]phenyl-κC1 (LSC), proceeded under proton transfer and replacement of the acac ligand, giving rise to O,P-bridged phosphanylcarboxylate dimers [LYCPd(μ(P,O)- L1)]2 and molecular chelates [LYCPd(L2-κ2O,P)]2, respectively. The analogous reactions involving 1'-(diphenylphosphanyl)-1-ferrocenecarboxylic acid (Hdpf) provided the macrocyclic tetramer [LNCPd(μ(P,O)-dpf)]4 and the dimer [LSCPd(μ(P,O)-dpf)]2. The reactions of HL1 with [Pd(acac)2] only led to an ill-defined, insoluble material, whereas those with HL2 produced a separable mixture of the bis-chelate complexes trans-[Pd(L2-κ2O,P)2], cis- [Pd(L2-κ2O,P)2], and [Pd(acac)(L2-κ2O,P)]. [ABSTRACT FROM AUTHOR]

Ferrocene P,N-ligands have been extensively studied due to their favorable catalytic properties. This contribution focuses on a pair of new, isomeric ferrocene phosphinoamines, FcNHCH 2 CH 2 PPh 2 (1) and FcN(Me)CH 2 PPh 2 (2), which were prepared from aminoferrocene, converted to the respective phosphine selenides (1-Se and 2-Se) and further studied as ligands in Pd(II) complexes containing the 2-(dimethylamino-κ N)phenyl-κ C 1 auxiliary (LNC) ligand. Thus, cleavage of the dimeric precursor [(LNC)Pd(μ-Cl)] 2 with the phosphinoamines afforded the corresponding phosphine complexes [(LNC)PdCl(1 -κ P)] (5) and [(LNC)PdCl(2 -κ P)] (6) with trans -P,N configuration. The subsequent removal of the chloride ligand with AgClO 4 from 5 produced the cationic bis-chelate complex [(LNC)PdCl(1 -κ2 P,N)]ClO 4 (7), whereas an analogous reaction with 6 gave no defined product. The phosphinoamines and their complexes were characterized by elemental analysis and common spectroscopic methods, and the crystal structures of 1, 2 , and 7 were determined by single-crystal X-ray diffraction analysis. A cyclic voltammetry study, supported by DFT calculations, revealed that the primary electrochemical oxidation of these compounds occurs at the ferrocene unit. [ABSTRACT FROM AUTHOR]

Acylation of 1′-(diphenylphosphino)-1-(aminocarbonyl)ferrocene, Ph 2 PfcCONH 2 ( 1 ; fc = ferrocene-1,1′-diyl), afforded a series of acyl-ureas including Ph 2 PfcCONHCONHEt ( 1a ), Ph 2 PfcCONHCONHPh ( 1b ), and Ph 2 PfcCONHCONMe 2 ( 1c ) as well as the acetyl derivative Ph 2 PfcCONHAc ( 1d ). Compounds 1a-d were converted to the corresponding phosphine oxides ( 2a-d ) and further examined as ligands in Pd(II) complexes. The reactions of 1a-d with [PdCl 2 (cod)] (cod = cycloocta-1,5-diene) at a 2:1 ligand-to-metal ratio gave the bis(phosphine) complexes [PdCl 2 (L-κ P ) 2 ] ( 3a-d ; L = 1a-d ), whereas the reactions with [Pd(L NC )Cl] 2 (L NC = [2-(dimethylamino-κ N )methyl]phenyl-κ C 1 ) produced the bridge-cleavage products, [PdCl(L NC )(L-κ P )] ( 4a-d ). Removal of the Pd-bound halide from 4a-d with Ag[SbF 6 ] furnished the corresponding cationic bis-chelate complexes [Pd(L NC )(L-κ 2 O,P )][SbF 6 ] ( 5a-d ). All compounds were characterized by NMR and IR spectroscopy, electrospray ionization mass spectrometry, and elemental analysis. The crystal structures of 1a , 2a-c , 3a ·2CHCl 3 , 3b ·2CHCl 3 , 3d ·2CHCl 3 , 4a ·3CHCl 3 , 4b ·2.5CHCl 3 , 5a ·CHCl 3 , 5b ·2CH 2 Cl 2 , and 5d were determined by single-crystal X-ray diffraction analysis, which revealed that the hydrogen-bonded arrays formed in the crystals of free ligands are often preserved in the structures of their complexes. [ABSTRACT FROM AUTHOR]

Removal of the chloride ligand from [AuCl( 1-κ P)] ( 2) containing a P-monodentate 1′-(diphenylphosphanyl)-1-cyanoferrocene ligand ( 1), by using silver(I) salts affords cationic complexes of the type [Au( 1)]X, which exist either as cyclic dimers [Au( 1)]2X2 ( 3 a, X=SbF6; 3 c, X=NTf2) or linear coordination polymers [Au( 1)] nX n ( 3 a′, X=SbF6; 3 b′, X=ClO4), depending on anion X and the isolation procedure. As demonstrated for 3 a′, the polymers can be readily cleaved by the addition of donors, such as Cl−, tetrahydrothiophene (tht) or 1, giving rise to the parent compound 2, [Au(tht)( 1-κ P)][SbF6] ( 5 a) or [Au( 1-κ P)2][SbF6] ( 4 a), respectively, of which the last two compounds can also be prepared by stepwise replacement of tht in [Au( 1-κ P)2][SbF6]. The particular combination of a firmly coordinated (phosphane) and a dissociable (nitrile) donor moieties renders complexes 3/3′ attractive for catalysis because they can serve as shelf-stable precursors of coordinatively unsaturated AuI fragments, analogous to those that result from the widely used [Au(PR3)(RCN)]X catalysts. The catalytic properties of the Au- 1 complexes were evaluated in model annulation reactions, such as the synthesis of 2,3-dimethylfuran from ( Z)-3-methylpent-2-en-4-yn-1-ol and oxidative cyclisation of alkynes with nitriles to produce 2,5-disubstituted 1,3-oxazoles. Of the compounds tested ( 2, 3 a′, 3 b′, 3 a, 4 a and 5 a), the best results were consistently achieved with dimer 3 c, which has good solubility in organic solvents and only one firmly bound donor at the gold atom. This compound was advantageously used in the key steps of annuloline and rosefuran syntheses. [ABSTRACT FROM AUTHOR]

{[Tris(hydroxymethyl)methylamino]carbonyl}ferrocene ( 1 ) reacts with phosphorus(III) chloride in the presence of pyridine or triethylamine to afford a ferrocenyl-substituted bicyclic phosphite, {[(2,6,7-trioxa-1-phosphabicyclo[2.2.2]oct-4-yl)amino]carbonyl}ferrocene ( 2 ), in a moderate yield. (4,5-Dihydro-4,4-bis(chloromethyl)-2-oxazolyl)ferrocene ( 3 ) is found to be formed in some experiments as a minor side-product, resulting presumably via halogenation of 1 and base-induced cyclization of an intermediate chloromethyl derivative. The reaction of 2 with [W(CO) 4 (cod)] (cod = cycloocta-1,5-diene) at elevated temperature produces bis-phosphite complex cis -[W(CO) 4 ( 2 -κ P ) 2 ] ( 4 ) as the major product. All newly prepared compounds have been characterized by spectroscopic methods (IR, NMR and mass spectrometry) and elemental analysis. The crystal structures of 2 , 3 ·1/2H 2 O and 4 ·Me 2 CO·H 2 O were determined by single-crystal X-ray diffraction and the redox behaviour of phosphite 2 and the W(0) complex 4 was studied by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

Bis(dimethylsulfido)decaborane, 6,9-(Me2S)2- arachno-B10H12, reacts smoothly with ferrocenyl alkynes FcC≡CR [ 1a- h; Fc = ferrocenyl, R = H ( 1a), CH3 ( 1b), Ph ( 1c), 4-MeO2CC6H4 ( 1d), Fc ( 1e), C≡CFc ( 1f), C(O)CH3 ( 1g), and CO2CH2CH3 ( 1h)] to afford the corresponding 1-ferrocenyl-1,2-dicarba- closo-dodecaboranes 2a- h in good yields. Ester 2h was further reduced to the respective hydroxymethyl derivative, 1-Fc-2-CH2OH-1,2- closo-C2B10H10 ( 3). The reaction of 6,9-(Me2S)2-B10H12 with FcC≡CSiMe3 proceeded in a different manner to produce (among other products) an SMe2 adduct of an opened decaborane substituted with a 2-ferrocenyl-2-(trimethylsilyl)ethen-1-yl group ( 4). This compound probably results through hydroboration of the starting alkyne and migration of the SiMe3 group. All prepared compounds were characterized by spectroscopic methods (1H, 13C, and 11B NMR spectroscopy, IR spectroscopy, and mass spectrometry), and their molecular structures were determined by single-crystal X-ray diffraction analysis. In addition, the compounds were studied by cyclic and differential pulse voltammetry on a platinum disc electrode to reveal simple ferrocenyl-centered oxidations for the singly ferrocenylated carboranes and two consecutive oxidation waves for compounds 2e and 2f, which possess two ferrocenyl substituents. [ABSTRACT FROM AUTHOR]

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: Depending on the reaction stoichiometry, 1-(diphenylphosphino)-1′-[(diphenylphosphino)methyl]-ferrocene (1) reacts with [AuCl(tht)] (tht = tetrahydrothiophene) to afford an insoluble polymer formulated as [AuCl(1)] n (2) or ligand-bridged digold(I) complex, [(μ-1)(AuCl)2] (3). The latter compound readily undergoes metathesis reactions with anionic reagents such as in situ generated acetylides, thiocyanate or N,N-diethyldithiocarbamate to give the corresponding digold(I) complexes [(μ-1)(AuY)2], where Y is Cbold>4), Cbold>5; Fc = ferrocenyl), SCN (6), and Et2NCS2 (7). Similar reaction of 3 with a dithiolate formed from propane-1,3-dithiol and sodium methoxide affords a macrocyclic bis-chelate [(μ-1)(AuSCH2CH2CH2SAu)] (8). Compounds 2–8 have been characterized by spectroscopic methods (multinuclear NMR, ESI, MS, UV–vis and IR) and by elemental analysis, and the molecular structures of 3·½C2H4Cl2, 4·2CHCl3, 7·2CHCl3, and 8 have been determined by single-crystal X-ray diffraction analysis. Cyclic voltammetric study revealed that ligand 1 undergoes a one-electron oxidation at the ferrocene unit, which is associated with some chemical complications resulting presumably from the presence of the lone electron pair at phosphorus. After coordination to Au(I)L fragments bearing simple auxiliary ligands (e.g., in 3, 4, and 6), the FeII/FeIII redox process becomes reversible and appears shifted to more positive potentials owing to an electron density transfer from the diphosphine ligand to the coordinated metal centers. For compounds 5 and 7, this redox change is accompanied by additional waves attributable to oxidation of ferrocenyl groups in the terminal ferrocenylethynyl groups and to redox changes occurring at the Au-bound carbamate ligands, respectively. [Copyright &y& Elsevier]

Abstract: Triorganotin chlorides Me3SnCl and (LNC)Me2SnCl (LNC =2-[(dimethylamino)methyl]phenyl) reacted with potassium 1′-(diphenylphosphino)-1-ferrocenecarboxylate to give the respective carboxylates, Ph2PfcCO2SnMe3 (1) and Ph2PfcCO2SnMe2(LNC) (2; fc=ferrocene-1,1′-diyl), while the analogous triphenylstannyl derivative 3 resulted by condensation of Ph3SnOH with 1′-(diphenylphosphino)-1-ferrocenecarboxylic acid (Hdpf). Compounds 1 and 2 were smoothly oxidized with hydrogen peroxide or elemental sulfur to afford the corresponding P-chalcogen derivatives (P-oxides 1a and 2a; P-sulfides 1b and 2b). All compounds were characterized by multinuclear NMR, IR and mass spectroscopy, and the solid-state structures of 1, 1a, 2, 2a and 2b were determined by single-crystal X-ray diffraction. In the crystal structures of 1 and 1a, the tin atoms were found with distorted trigonal bipyramidal coordination environments completed by the C:glyph name="dbnd" />O oxygens, respectively, from adjacent molecules, which in turn resulted in the formation of infinite linear assemblies. Tin atoms in 2, 2a, and 2b were found with trigonal bipyramidal surrounding as well, though with the donor substituent LNC assuming one of the axial donor sites. Compounds 2 and 2a crystallized as stoichiometric hydrates (2·1/2H2O, 2a·H2O), in which the water molecules served as hydrogen bond donors for the polar groups (Ce:glyph name="dbnd" />O) and thus aided the formation of closed H-bonded assemblies; the structure of 2b was essentially molecular. [Copyright &y& Elsevier]

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]

• Gold(I) complexes with N -phosphinoamide ligands were prepared. • Crystal structures were determined. • Interplay of intermolecular interactions of various types was observed in the solid state. [AuCl{RC(O)NHPPh 2 -κ P }] gold(I) complexes with varying amide substituents (R = Me, Ph and ferrocenyl) were prepared, characterized by elemental analysis and spectroscopic methods (mass spectrometry and multinuclear NMR and IR spectroscopy) and further studied by single-crystal X-ray crystallography with a particular focus on solid-state interactions. In all cases, the crystal assembly was based mainly on conventional hydrogen bonds between the amide moieties. However, while in chloroform-solvated [AuCl{MeC(O)NHPPh 2 -κ P }], these interactions were supported by π⋅⋅⋅π stacking of aromatic rings, in the crystal structures of the complexes bearing phenyl and ferrocenyl substituents, they cooperated with aurophilic interactions of the Au(I) centers, which in turn affected the C O⋯HN hydrogen bonds. [ABSTRACT FROM AUTHOR]

Keywords: metallocenes; phosphanes; primary phosphane chalcogenides; structure elucidation; synthesis EN metallocenes phosphanes primary phosphane chalcogenides structure elucidation synthesis 1161 1161 1 01/20/21 20210118 NES 210118 B Isolable primary phosphane oxides RP(O)H SB 2 sb b have remained elusive, unlike their secondary counterparts R SB 2 sb P(O)H, which have been used in various applications. This work reports the synthesis and characterization of (ferrocenylmethyl)phosphane oxide as the first bench-stable primary phosphane oxide. [Extracted from the article]

• A multidonor amidophosphine ligand was prepared using an alternative route. • The ligand reacts with group 10 metal dichloride precursors to produce P,N,N-chelate complexes. • Spontaneous HCl elimination occurs during the complexation. • Terminal chloride ligand can be replaced for a phosphine. • The complexes were fully characterized and possess similar molecular structures. The multidonor amidophosphine 2-Ph 2 PC 6 H 4 NHC(O)C 5 H 4 N, where C 5 H 4 N is a 2-pyridyl substituent, reacted with the synthetic equivalents of group 10 metal dichlorides, viz. [NiCl 2 (dme)], [PdCl 2 (MeCN) 2 ] or [PtCl 2 (cod)] (dme = 1,2-dimethoxyethane, cod = cycloocta-1,5-diene), to produce neutral bis-chelate complexes [MCl(Ph 2 PC 6 H 4 NC(O)C 5 H 4 N-κ3 P,N,N ′)] (M = Ni, Pd, and Pt). During the complexation reaction, spontaneous HCl elimination occurred, possibly as the result of overall structural stabilization by the deprotonation of the amide nitrogen, which is brought toward the metal centers by initial P,N(pyridine)-coordination of the amidophosphine ligand. Subsequent reaction of 3 as the representative with AgClO 4 and triphenylphosphine produced the cationic bis(phosphine) complex [Pd(PPh 3)(Ph 2 PC 6 H 4 NC(O)C 5 H 4 N-κ3 P,N,N ′)]ClO 4 (5), which converted back to parent chloride complex in the presence of chloride ions. All complexes were fully characterized using NMR and IR spectroscopy, mass spectrometry, and elemental analysis. X-ray diffraction analysis for 2, 3, 4 ·½ CH 2 Cl 2 and 5 ·Me 2 CO revealed that compounds 2 – 4 exhibit similar coordination geometry, which is rather marginally affected upon replacement of the chloride for a bulkier phosphine ligand. [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]

Elusive, highly catalytically active gold(I) complexes are formed within the equilibrium between the polymeric, dimeric, and presumed mono ‐ gold(I) cationic complexes containing the bifuctional and hemilabile 1′ ‐ (diphenylphosphanyl) ‐ 1 ‐ cyanoferrocene supporting ligand. These species are capable of catalyzing annelation reactions of various organic substrates, and were employed during the key steps of the synthesis of rosefurane and annuloline (see picture, bottom structures). The overall concept is depicted on the background picture of the Czech mythical mountain Říp, the relatively flattened shape of which may resemble the energy barrier occurring en route from the starting materials to the products in a transition ‐ metal ‐ catalyzed process. For further details see the Full Paper by P. Štěpnička and colleagues on page 15998 ff. [ABSTRACT FROM AUTHOR]

The reactions of 1’-(diphenylphosphino)-1-(hydrazinylcarbonyl)ferrocene, Ph 2 PfcCONHNH 2 ( 1 ; fc = ferrocene-1,1′-diyl), with HNCO, EtNCO, PhNCO, Me 2 NC(O)Cl/pyridine, and Ac 2 O/NEt 3 produced the corresponding N -functionalized derivatives Ph 2 PfcCONHNHC(O)Y ( 1a-e ), where Y = NH 2 ( a ), NHEt ( b ), NHPh ( c ), NMe 2 ( d ), and Me ( e ). Compounds 1a-e were used as ligands (L) to prepare Pd(II) bis(phosphine) complexes [PdCl 2 (L-κ P ) 2 ] ( 3a-e ) and two series of Pd(II) complexes bearing an auxiliary 2-[(dimethylamino-κ N )methyl]phenyl-κ C 1 (L NC ) ligand, namely, [(L NC )PdCl(L-κ P )] ( 4a-e ) and [(L NC )Pd(L-κ 2 O , P )][SbF 6 ] ( 5a-e ). The crystal structures of compounds 1a , 1c , 1e , the phosphine oxide of 1e (i.e., compound 2e ), and complexes 3c ·4CH 2 Cl 2 ·2CH 3 OH, 3e ·4CH 3 OH, 4e , and 5e ·2.5CHCl 3 were determined by single-crystal X-ray diffraction analysis. Hydrogen bonding interactions observed in the solid-state structures of these compounds are discussed. [ABSTRACT FROM AUTHOR]

Bis{[1′-(diphenylphosphino)ferrocenyl]methyl}ether ( 3 ) was prepared in two steps from the [1′-(diphenylphosphino)ferrocenyl]methanol−borane (1:1) adduct and structurally characterized. Compound 3 reacted with copper(I) halides to afford structurally similar, cyclic binuclear complexes of the type [CuX{μ(P,P′)- 3 }] 2 (X = Cl, Br and I) featuring equivalent Cu(I) centers with trigonal P 2 X donor sets symmetrically bridged by the diphosphine ligand. [ABSTRACT FROM AUTHOR]

Two phosphinoferrocene carboxylic acids differing in the two-carbon spacer separating the phosphinoferrocene moiety and the carboxyl group, Ph 2 PfcCH=CHCO 2 H ( 1a ) and Ph 2 PfcCH 2 CH 2 CO 2 H ( 1b ; fc = ferrocene-1,1′-diyl), were prepared from aldehyde Ph 2 PfcCHO by Horner-Wadsworth-Emmons olefination, reduction and hydrolysis. These acids reacted with [(L NC )Pd(acac)] (L NC = 2-[(dimethylamino-κ N )methyl]phenyl-κ C 1 , acac = pentane-2,5-dionate) under protonation and elimination of the Pd-bound acetylacetonate ligand to afford the respective phosphinocarboxylate complexes, namely, the P,O-bridged dimer [(L NC )Pd{μ(P,O)-Ph 2 PfcCH=CHCO 2 }] 2 ( 6a ) and the coordination polymer [(L NC )Pd{μ(P,O)-Ph 2 PfcCH 2 CH 2 CO 2 }] n ( 6a ). The crystal structures of P-sulfides prepared from acids 1a and 1b , compounds Ph 2 P(S)fcCH=CH 2 CO 2 H and Ph 2 P(S)fcCH 2 CH 2 CO 2 H, and the phosphinocarboxylate complexes 6a and 6b (in solvated form) were determined by single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Several approaches to the intramolecular activation of a pendant nitrile group attached to the group 4 metallocene framework have been probed starting with the complexes [(η 5 -C 5 Me 5 )(η 5 -C 5 H 4 CMe 2 CH 2 CN)MCl 2 ] (M = Zr, 1 ; M = Ti, 2 ). A reduction induced activation of the nitrile moiety was effected for the Zr derivative either by the treatment with Mg, or by the alkylation using t -BuMgCl followed by spontaneous reductive elimination. In both cases, the reactions finally yielded the zirconocene cyano complex with an intramolecularly tethered alkyl substituent, [(η 5 -C 5 Me 5 )(η 5 :κ C 1 -C 5 H 4 CMe 2 CH 2 )Zr(CN-κ C )] ( 4 ), which resulted from the C–C bond cleavage in the pendant arm. Furthermore, a by-product was isolated which contained two zirconocene fragments bridged through a MgCl 2 moiety featuring a rare σ , π -bridging mode of the pendant nitrile group, [{(η 5 -C 5 Me 5 )(μ-η 5 :η 2 :κ N -C 5 H 4 CMe 2 CH 2 CN)(μ-Cl)Zr} 2 Mg] ( 3 ). The solid-state structure of 3 was elucidated and this compound together with the product 4 and the tentative intermediate [{(η 5 -C 5 Me 5 )(η 5 :η 2 -C 5 H 4 CMe 2 CH 2 CN)Zr] ( 3′ ) were also investigated by DFT calculations. In another approach, 1 and 2 were treated with Li[B(C 6 F 5 ) 4 ]∙Et 2 O to generate cationic complexes. Accidental hydrolysis of these species afforded complexes bearing an intramolecularly tethered amide group [{(η 5 -C 5 Me 5 )(η 5 :κ O -C 5 H 4 CMe 2 CH 2 CONH 2 )M], of which the Ti derivative ( 6 ) was isolated and structurally characterised. Finally, reaction of the zirconocene dimethyl complex [(η 5 -C 5 Me 5 )(η 5 -C 5 H 4 CMe 2 CH 2 CN)ZrMe 2 ] ( 8 ) with (Ph 3 C)[B(C 6 F 5 ) 4 ] was studied. [ABSTRACT FROM AUTHOR]

• 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]

Abstract: Two polar phosphinoferrocene ligands, 1′-(diphenylphosphino)ferrocene-1-carboxamide (1) and 1′-(diphenylphosphino)ferrocene-1-carbohydrazide (2), were synthesized in good yields from 1′-(diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf) via the reactive benzotriazole derivative, 1-[1′-(diphenylphosphino)ferrocene-1-carbonyl]-1H-1,2,3-benzotriazole (3). Alternatively, the hydrazide was prepared by the conventional reaction of methyl 1′-(diphenylphosphino)ferrocene-1-carboxylate with hydrazine hydrate, and was further converted via standard condensation reactions to three phosphinoferrocene heterocycles, viz 2-[1′-(diphenylphosphino)ferrocen-1-yl]-1,3,4-oxadiazole (4), 1-[1′-(diphenylphosphino)ferrocen-1-carbonyl]-3,5-dimethyl-1,2-pyrazole (5), and 1-[1′-(diphenylphosphino)ferrocene-1-carboxamido]-3,5-dimethylpyrrole (6). Compounds 1 and 2 react with [PdCl2(cod)] (cod = η2:η2-cycloocta-1,5-diene) to afford the respective bis-phosphine complexes trans-[PdCl2(L-κP)2] (7, L = 1; 8, L = 2). The dimeric precursor [(LNC)PdCl]2 (LNC = 2-[(dimethylamino-κN)methyl]phenyl-κC 1) is cleaved with 1 to give the neutral phosphine complex [(LNC)PdCl(1-κP)] (9), which is readily transformed into a ionic bis-chelate complex [(LNC)PdCl(1-κ2 O,P)][SbF6] (10) upon removal of the chloride ligand with Ag[SbF6]. Pyrazole 5 behaves similarly affording the related complexes [(LNC)PdCl(5-κP)] (12) and [(LNC)PdCl(5-κ2 O,P)][SbF6] (13), in which the ferrocene ligand coordinates as a simple phosphine and an O,P-chelate respectively, while oxadiazole 4 affords the phosphine complex [(LNC)PdCl(4-κP)] (11) and a P,N-chelate [(LNC)PdCl(4-κ2 N 3 ,P)][SbF6] (14) under similar conditions. All compounds were characterized by elemental analysis and spectroscopic methods (multinuclear NMR, IR and MS). The solid-state structures of 1⋅½AcOEt, 2, 7⋅3CH3CN, 8⋅2CHCl3, 9⋅½CH2Cl2⋅0.375C6H14, 10, and 14 were determined by single-crystal X-ray crystallography. [Copyright &y& Elsevier]

(2-Azoniaethyl)guanidinium dichloride ( AEGCl ), a salt of a functional guanidine derivative, was prepared and characterised by single-crystal and powder X-ray diffraction analysis, elemental analysis and by NMR, UV–Vis and vibrational spectroscopy. The crystal structure of AEGCl , which crystallises with the symmetry of the chiral space group P 2 1 , is built up via simple and multicentred N H⋯Cl hydrogen bonds and further supported by C H⋯Cl contacts. The compound is thermally robust and exhibits promising NLO properties with powder SHG efficiency better than potassium dihydrogen phosphate. In contrast, (2-azoniaethyl)guanidinium salts with inorganic oxoanions such as (2-azoniaethyl)guanidinium dinitrate and diperchlorate, synthesised for a comparison, form centrosymmetric crystal assemblies having several structurally independent “molecules” in their structures. [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]

Abstract: The reaction of in situ generated 1′-(diphenylphosphino)-1-lithioferrocene with isocyanates RNCO affords the respective phosphino-carboxamides Ph2PfcCONHR (fc=ferrocene-1,1′-diyl, R=cyclohexyl (2), and Ph (3)) in moderate yields. The coordination behaviour of 3 chosen as a representative was studied in palladium(II) and platinum(II) complexes. Depending on the metal precursor and the reaction conditions, the following compounds featuring this ligand as a P-monodentate or an O,P-chelating donor were isolated and characterised by spectroscopic methods (IR, multinuclear NMR and electrospray ionisation MS): trans-[PdCl2(3-κP)2] (5), trans-[PtCl2(3-κP)2] (6), cis-[PtCl2(3-κP)2] (7), [SP-4-4]-[(LNC)PdCl(3-κP)] (8; LNC =2-[(dimethylamino-κN)methyl]phenyl-κC 1), and [SP-4-3]-[(LNC)PdCl(3-κ2 O,P)]SbF6 (9). Besides, the crystal structures of a phosphine oxide resulting by oxidation of 2, viz Ph2P(O)fcCONHCy (4), and of complexes 5·2Et2O and 9 have been determined by single-crystal X-ray diffraction analysis. [Copyright &y& Elsevier]

Abstract: Amide coupling between [2-(diphenylphosphino)phenyl]methylamine and 1′-(diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf) afforded a novel diphosphine-amide, 1-{N-[(2-(diphenylphosphino)phenyl)methyl]carbamoyl}-1′-(diphenylphosphino)ferrocene (1), which was subsequently studied as a ligand for palladium(II) complexes. Depending on the metal precursor, the following complexes were isolated: [PdCl2(1-κ2 P,P′)] (2), [PdCl(Me)(1-κ2 P,P′)] (3), [(μ-1){PdCl2(PBu3)}2] (4) and [(μ-1){PdCl(LNC)}2] (LNC =2-[(dimethylamino-κN)methyl]phenyl-κC 1), featuring this ligand either as a trans-chelating or as a P,P′-bridging donor. The crystal structure of 2·1.25CH2Cl2 was established by X-ray crystallography, corroborating that 1 coordinates as a trans-spanning diphosphine without any significant distortion to the coordination sphere. Complex 2 together with a catalyst prepared in situ from 1 and palladium(II) acetate were tested in Suzuki–Miyaura reaction of aryl bromides with phenylboronic acid in dioxane. [Copyright &y& Elsevier]