- FERROCENOPHANES WITH PHOSPHORUS AND ARSENIC AS THE BRIDGING ATOMS: SYNTHESIS AND SOME REACTIONS. A NEW ROUTE TO FERROCENYLLITHIUM REAGENTS
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(1,1'-Ferrocenediyl)phenyl-phosphine and -arsine and (1,1'-ferrocenediyl)-methylphosphine have been prepared by the reaction of 1,1'-dilithioferrocenetetramethylethylenediamine with the respective RPCl2 and PhAsCl2.They react at the Group V bridging atom with sulfur and with reactive metal carbonyl species without disruption of the ferrocenophane system.Organolithium reagents react with these compounds to open the ring and give 1-lithio-1'-phosphino- or arsino-ferrocenes.Some reactions of these new lithium reagents are reported.
- Seyferth, Dietmar,Withers, Howard P.
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- A ferrocene diphosphine ligand preparation method
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The invention discloses a method for preparing ferrocene diphosphine ligand, and belongs to the field of organic synthesis. The method comprises the following steps: by taking ferrocene as an initial raw material and boron trifluoride diethyl etherate as a catalyst, reacting with diaryl phosphine oxide or dialkyl phosphine oxide, hydrolyzing so as to obtain tertfluoborate of a ferrocene diphosphine compound, and performing heating backflow deprotection in methanol, thereby obtaining the ferrocene diphosphine compound. Compared with the prior art, the method is gentle in reaction condition, simple in aftertreatment, and relatively applicable to industrial production, and the yield is greater than 90%. The prepared ferrocene diphosphine can be used as ligand of a metal catalyst, and can be used in the fields such as organic optoelectronic materials and medicines.
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Paragraph 0006; 0015; 0016
(2017/08/31)
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- Chemoselective Reduction of Phosphine Oxides by 1,3-Diphenyl-Disiloxane
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Reduction of phosphine oxides to the corresponding phosphines represents the most straightforward method to prepare these valuable reagents. However, existing methods to reduce phosphine oxides suffer from inadequate chemoselectivity due to the strength of the P=O bond and/or poor atom economy. Herein, we report the discovery of the most powerful chemoselective reductant for this transformation to date, 1,3-diphenyl-disiloxane (DPDS). Additive-free DPDS selectively reduces both secondary and tertiary phosphine oxides with retention of configuration even in the presence of aldehyde, nitro, ester, α,β-unsaturated carbonyls, azocarboxylates, and cyano functional groups. Arrhenius analysis indicates that the activation barrier for reduction by DPDS is significantly lower than any previously calculated silane reduction system. Inclusion of a catalytic Br?nsted acid further reduced the activation barrier and led to the first silane-mediated reduction of acyclic phosphine oxides at room temperature.
- Buonomo, Joseph A.,Eiden, Carter G.,Aldrich, Courtney C.
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supporting information
p. 14434 - 14438
(2017/10/23)
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- Metal-Free Reduction of Phosphine Oxides, Sulfoxides, and N-Oxides with Hydrosilanes using a Borinic Acid Precatalyst
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The general reduction of phosphine oxides, sulfoxides, and amine N-oxides was achieved by combining bis(2-chlorophenyl)borinic acid with phenylsilane. The reaction was shown to tolerate a wide range of substrates and could be performed under mild conditions, with only 2.5 mol % of the easily synthesized catalyst. Mechanistic investigations pointed to a key borohydride as the real catalyst and at bis(2-chlorophenyl)borinic acid as a precatalyst.
- Chardon, Aurélien,Maubert, Orianne,Rouden, Jacques,Blanchet, Jér?me
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p. 4460 - 4464
(2017/11/22)
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- Highly efficient reduction of tertiary phosphine oxides and sulfides with amine-assisted aluminum hydrides under mild conditions
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Reduction of tertiary phosphine oxides and sulfides into the corresponding phosphines with amine-assisted aluminum hydrides has been studied. The method is characterized by mild conditions, short reaction time, high efficiency, and expanded substrate scope. The new method is an alternative to the currently used methods of reducing phosphine oxides or recycling phosphines engaged in organic reactions.
- Yang, Shuyan,Han, Xinxin,Luo, Minmin,Gao, Jing,Chu, Wenxiang,Ding, Yuqiang
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p. 1156 - 1160
(2015/06/30)
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- Acceptor-substituted ferrocenium salts as strong, single-electron oxidants: Synthesis, electrochemistry, theoretical investigations, and initial synthetic application
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A series of mono- and 1,1'-diheteroatom-substituted ferrocene derivatives as well as acylated ferrocenes was prepared efficiently by a unified strategy that consists of selective mono- and 1,1'-dilithiation reactions and subsequent coupling with carbon, phosphorus, sulfur and halogen electrophiles. Chemical oxidation of the ferrocene derivatives by benzoquinone, 2,3-dichloro-5,6- dicyanobenzoquinone, AgPF6, or 2,2,6,6-tetramethyl-1-oxopiperidinium hexafluorophosphate provided the corresponding ferrocenium salts. The redox potentials of the synthesized ferrocenes were determined by cyclic voltammetry, and it was observed that all new ferrocenium salts have stronger oxidizing properties than standard ferrocenium hexafluorophosphate. An initial application of selected derivatives in an oxidative bicyclization revealed that they mediate the transformation under considerably milder conditions than ferrocenium hexafluorophosphate. Quantum chemical calculations of the reduction potentials of the substituted ferrocenium ions were carried out by using a standard thermodynamic cycle that involved the gas-phase energetics and solvation energies of the contributing species. A remarkable agreement between theory and experiment was found: the mean average deviation amounted to only 0.030-V and the maximum deviation to 0.1-V. This enabled the analysis of various physical contributions to the computed reduction potentials of these ferrocene derivatives, thereby providing insight into their electronic structure and physicochemical properties. Copyright
- Khobragade, Dushant A.,Mahamulkar, Shraddha G.,Pospí?il, Lubomír,Císa?ová, Ivana,Rulí?ek, Lubomír,Jahn, Ullrich
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supporting information
p. 12267 - 12277
(2012/11/14)
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- A PROCESS FOR THE REDUCTION OF A TERTIARY PHOSPHINE OXIDE TO THE CORRESPONDING TERTIARY PHOSPHINE IN THE PRESENCE OF A CATALYST AND USE OF A TERTIARY PHOSPHINE FOR REDUCING A TERTIARY PHOSPHINE OXIDE IN THE PRESENCE OF A CATALYST
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A process for the conversion of a tertiary phosphine oxide to the corresponding tertiary phosphine comprising reacting said tertiary phosphine oxide with a reducing tertiary phosphine, in the presence of a catalyst that catalyzes the conversion.
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Page/Page column 23
(2011/10/13)
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- Homoleptic complexes of cobalt(0) and nickel(0,I) with 1,1′- bis(diphenylphosphino)ferrocene (dppf): Synthesis and characterization
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Reduction of Co(dppf)Cl2 with 2 equiv of sodium naphthalenide in THF, in the presence of dppf, affords the homoleptic complex Co(dppf) 2, 1, isolated in 65% yield as a brick red solid, extremely air sensitive. In solution, under inert atmosphere, 1 slowly decomposes into Co and dppf, following a first-order kinetic law (t1/2 = 21 h at 22°C). Similarly to the Rh and Ir congeners, 1 undergoes a one-electron reversible reduction to [Co(dppf)2]-. Attempts to obtain this d 10 species by chemical as well as electrochemical reduction of 1 lead to the hydride HCo(dppf)2, 2, as the only product that can be isolated. Reduction of Ni(dppf)Cl2 with sodium in the presence of dppf and catalytic amounts of naphthalene affords Ni(dppf)2, 3, isolated in 60% yield as a yellow air stable solid. The stoichiometric oxidation of 3 with [FeCp2]PF6 forms the d9 complex [Ni(dppf)2]PF6, 4, which represents the second example of a structurally characterized Ni(I) complex stabilized by phosphines. A single-crystal X-ray analysis shows for the metal a distorted tetrahedral environment with a dihedral angle defined by the planes containing the atoms P(1), Ni, P(2) and P(3), Ni, P(4) of 78.2° and remarkably long Ni-P bond distances (2.342(3)-2.394(3) A). The EPR spectroscopic properties of 1 (at 106 K in THF) and 4 (at 7 K in 2-methyl-THF) have been examined and g tensor values measured (1, gx = 2.008, gy = 2.182, gz = 2.326; 4, gx = 2.098, gy = 2.113, gz = 2.332). A linear dependence between the hyperfine constants and the Ni-P bond distances has been evidenced. Finally, the change with time of the EPR spectrum of 4 indicates that it very slowly releases dppf.
- Pilloni, Giuseppe,Toffoletti, Antonio,Bandoli, Giuliano,Longato, Bruno
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p. 10321 - 10328
(2008/10/09)
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- General route to dissymmetric heteroannular-functionalized ferrocenyl 1,2-diphosphines: Selective synthesis and characterization of a new class of tri- and tetrasubstituted ferrocenyl compounds
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Several monosubstituted-cyclopentadienyl anions (A-Li) and [1,2-bis(diphenylphosphino)-4-tert-butylcyclopentadienyl]lithium (B-Li) react with FeCl2 to afford a novel class of multidentate ferrocenylphosphines (A-Fe-B). The proposed synthetic method represents a unique means to produce achiral dissymmetric 1,1′,2-substituted ferrocenes (A-Fe-B) bearing a heteroannular 1′-substituent which is different from the homoannular 1- and 2-substituents. The selectivity for the two-step reaction favors formation of the desired dissymmetric product (A-Fe-B) rather than the concurrent formation of the symmetric di- and tetrasubstituted ferrocenes (A-Fe-A and B-Fe-B). Therefore, this method allows access to a great number of dissymmetric multidentate metalloligands, especially when one considers that functionalized-Cp salts continue to expand in terms of number and diversity. Herein, emphasis was placed upon the 1H, 13C, and 31P NMR characterization of the metalloligands; several examples exhibit intriguing conformational properties and rare through-space phosphorus nuclear-spin couplings.
- Ivanov,Hierso,Amardeil,Meunier
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p. 989 - 995
(2008/10/09)
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- Comparative reactivity studies of dppf-containing CpRuII and (C6Me6)RuII complexes towards different donor ligands (dppf=1,1′-bis(diphenylphosphino)ferrocene)
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[CpRu(dppf)Cl] (Cp=η5-C5H5) (1) and [(HMB)Ru(dppf)Cl]PF6 ((HMB)=η6-C6Me6) (3) react with different donor ligands to give rise to N-, P- and S-bonded complexes. The stoichiometric reactions of 1 and 3 with NaNCS give the mononuclear complexes [CpRu(dppf)(NCS)] (2) and [(HMB)Ru(dppf)(NCS)]PF6 (4), respectively, in yields above 80%, while 3 also gives a dppf-bridged diruthenium complex [(HMB)Ru(NCS)2]2 (μ-dppf) (5) in 67% yield from reaction with four molar equivalents of NaNCS. Compound 5 is also obtained in 70% yield from the reaction of 4 with excess NaNCS. With CH3CN in the presence of salts, both 1 and 3 give their analogous solvento derivatives [CpRu(dppf) (CH3CN)] BPh4 (6) and [(HMB)Ru(dppf) (CH3CN)] (PF6)2 (7). With phosphines, the reaction of 1 gives chloro-displaced complexes [(CpRu(dppf)L]PF6 (L =PMe3 (8), PMe2Ph(9), whereas the reaction of 3 with PMe2Ph leads to substitution of dppf, giving [(HMB)Ru(PMe2Ph)2Cl] PF6 (10). The reaction of 1 with NaS2CNEt2 gives a dinuclear dppf-bridged complex [{CpRu(S2CNEt2)} 2(μ-dppf)] (11), whereas that of 3 results in loss of the HMB ligand giving a mononuclear complex [Ru(dppf) (S2CNEt2)2] (12). With elemental sulfur S8, 1 is oxidized to give a dinuclear CpRuIII dppf-chelated complex [{CpRu(dppf)}2(μ-S2)] (BPh4)Cl (13), whereas 3 undergoes oxidation at the ligand, giving a dppf-displaced complex [(HMB)Ru(CH3CN)2Cl] PF6 (14) and free dppfS2. The structures of 1, 2, 5-9, 11, 13 and 14 were established by X-ray single crystal diffraction analyses. Of these, 5 and 11 both contain a dppf-bridge between RuII centers, while 13 is a dinuclear CpRuIII disulfide-bridged complex; all the others are mononuclear. All complexes obtained were also spectroscopically characterized.
- Lu, Xiu Lian,Vittal, Jagadese J.,Tiekink, Edward R.T.,Tan,Kuan, Seah Ling,Goh, Lai Yoong,Hor, T.S. Andy
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p. 1978 - 1990
(2007/10/03)
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- Preparation and crystal structures of syn-[(μ-SPh)Fe(CO)3]2, (C5H4SPh)2Fe, (C5H5)Fe(C5H4SPh), and (C5H4SPh)Fe(C5H4PPh2)
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The reaction of (C5H4SPh)2Fe with Fe2(CO)9 in MeCN at 25°C under photolytic conditions has been found to afford a dimer, [(μ-SPh)Fe(CO)3]2, whose X-ray structure exhibits a syn form. This reaction also yields (C5H5)Fe(C5H4SPh) as a byproduct, following the C-S bond cleavage. Stepwise functionalized of (C5H5)2Fe via selective transmetalation of (C5H4SnBu3)2Fe has led to the successful preparation of (C5H5)Fe(C5H4SPh) and (C5H4SPh)Fe(C5H4PPh2) in good yields. X-ray crystallographic studies of the title compounds have been carried out. (C5H4SPh)2Fe (2): monoclinic space group P21/c, a = 6.099 (3) A?, b = 7.855 (1) A?, c = 19.027 (3) A?, β = 99.12 (2)°, V = 902.2 A?3, Z = 2, 1976 data with I0 > 2.5σ(I0) refined to R = 0.029 and Rw = 0.035. (C5H5)Fe(C5H4SPh) (3): orthorhombic space group P212121, a = 7.307 (8) A?, b = 9.018 (9) A?,c = 20.033 (3) A?, V = 1320.1 A?3, Z = 4, 1054 data with I0 > 2.5σ(I0) refined to R = 0.026 and Rw = 0.028. (C5H4SPh)Fe(C5H4PPh2) (7): triclinic space group P1, a = 9.675 (2) A?, b = 10.903 (3) A?, c = 12.899 (3) A?, a = 112.89 (3)°, β = 86.89 (2)°, γ = 113.53 (2)°, V = 1141 A?3, Z = 2, 2567 data with I0 > 2.5σ(I0) refined to R = 0.032 and Rw = 0.040. syn- [(μ-SPh)Fe(CO)3]2 (8): orthorhombic space group Pbca, a = 7.151 (2) A?, b = 20.847 (3) A?, c = 27.155 (4) A?, V = 4048.0 A?3, Z = 8, 1247 data with I0 > 2.5σ(I0) refined to R = 0.043 and Rw = 0.043.
- Adeleke, J. Adebanjo,Chen, Yu-Wang,Liu, Ling-Kang
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p. 2543 - 2550
(2008/10/08)
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- Lithiophosphinoferrocenes. A route to polyphosphines and ring-substituted ferrocenophanes
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The metalation of Fe(C5H4PPh2)(C5H5) (7) by n-BuLi affords predominantly hetero-ring dilithiated products 8 best characterized by their reaction with S8 which yields the [3]ferrocenophanes Fe(C5H3(P-(S)Ph2)S-1,n)(C5H 4S2) (n = 3 (?75%) or 2 (?25%). The PPh2 group has some effect in directing the metalation of 7 to the 2-position. Reaction of 8 with ClPPh2 affords tris (tertiary phosphines) and with Cl2PPh affords [1]ferrocenophanes such as Fe(C5H3(PPh2)PPh-1,3)(C5H 4) (12a). Cleavage of 12a with RLi takes place so that the anion is formed predominantly in the PPh2-substituted ring allowing the preparation of compounds such as Fe(C5H3(PPh2)SiMe3-1,3)(C 5H4PPhMe). Some arsenic derivatives and related chemistry of Fe(C5H4PPh2)2 are also described.
- Butler, Ian R.,Cullen, William R.
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p. 2537 - 2542
(2008/10/08)
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- Phosphorus- and arsenic-bridge [1]ferrocenophanes. 1. Syvthesis and characterization
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The reaction of 1,1′-dilithiofeirocene-tetramethylethylenediamine with the respective phosphorus and arsenic dichioride was used in the preparation of (1,1′-fenocenediyljphenylphosphine and methyiphosphine and (1,1′-ferrocenediyl)phenylarsine. The reactions of these [1]ferrocenophanes are of two types: (a) those which occur with retention of the ferrocenopfaane system (e.g., those with elemental sulfur, with THF-W(CO)5, and Fe2(CO)9 in THF); (b) those which occur with opening of the ferrocenophane system. Phenyliithium and other RLi react in the latter manner to give 1-phosphino- {or 1-arsino-) 1′-lithioferrocenes whose reactions with several electrophiles were studied. The reaction of 1,1′-dilithioferrocene with diorganotin dichlorides gave 1,1,12,12-tetraalkyl[1,1]stannaferrocenophanes in very low yield, in addition to high yields of polymeric material.
- Seyfertr, Dietmar
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p. 1275 - 1282
(2008/10/08)
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