- Synthesis, characterization and third-order nonlinear optical properties of symmetrical ferrocenyl Schiff base materials
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Six symmetrical ferrocenyl Schiff base materials were synthesized and characterized by UV, 1H NMR, mass spectrometry (MS) and elemental analysis. Their off-resonant third-order nonlinear optical properties were measured using femtosecond laser
- Yu, Weiguo,Jia, Jianhong,Gao, Jianrong,Han, Liang,Li, Yujin
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- The highly regiospecific synthesis and crystal structure determination of 1,1′-2,5′ substituted ring-locked ferrocenes
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1,1′-Ferrocene biscarboxaldehyde (1) has been prepared and the aldehyde groups were subsequently protected with acetal groups to produce 1,1′-bisacetalferrocene (2). A ring-locked ferrocene was synthesised by further derivatisation of the cyclopentadiene
- Connell, Arthur,Holliman, Peter J.,Butler, Ian R.,Male, Louise,Coles, Simon J.,Horton, Peter N.,Hursthouse, Michael B.,Clegg, William,Russo, Luca
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- An improved synthesis of ferrocene-1,1'-dicarbaldehyde
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Ferrocene-1,1'-dicarbaldehyde has been prepared in 70percent yield in a one-pot procedure from dilithioferrocene-TMEDA complex and dimethylformamide.
- Balavoine, G. G. A.,Doisneau, G.,Fillebeen-Khan, T.
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- Preparation, characterization and electrochemical and X-ray structural studies of new conjugated 1,1′-ferrocenediyl-ended [CpFe-arylhydrazone] + salts
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A series of new conjugated bimetallic ferrocenyl 1,1′-bis- substituted compounds of the type (E)-[CpFe(η6-p-RC 6H4)NHN=CH(η5-C5H 4)Fe(η5-C5H4)-CH=CHC 6H4-p-R′]+PF6- (Cp = η5-C5H5; R, R′ = H, NO 2, 11; Me, NO2, 12; MeO, NO2, 13; Cl, NO 2, 14; Me, CN, 15; Me, Me, 16), with end-capped (E)-ethenylaryl and [CpFe(arylhydrazone)]+ substituents, have been prepared by the condensation reaction of 1,1′-(p-R′-arylethenyl) ferrocenecarboxaldehyde (R′ = Me, 4; NO2, 5; CN, 6) with the organometallic hydrazine precursors [CpFe(η6-p-RC 6H4NHNH2)]+PF6 - (R = H, 7; Me, 8; MeO, 9; Cl, 10). In the trimetallic series, {[CpFe(η6-p-RC6H4)NHN=CH(η 5-C5H4)]2Fe}2+[PF 6-]2 (R = H, 17; Me, 18; MeO, 19, Cl, 20), which results from the condensation of two equivalents of the same organometallic hydrazine precursor (7-10) with 1,1′- ferrocenedicarboxaldehyde, the ferrocenediyl core symmetrically links two cationic mixed-sandwich units. These ten hydrazones (11-20) were stereoselectively obtained as their trans isomers about the N=C double bond. All the new compounds were thoroughly characterized by a combination of elemental analysis, spectroscopic techniques (1H NMR, IR and UV-Vis) and electrochemical studies in order to prove electronic interaction between the donating and accepting units through the π-conjugated system. A representative example of each series has also been characterized by single crystal X-ray diffraction analysis. The bimetallic complex 16+ adopts an anti conformation with the two iron atoms on opposite faces of the dinucleating hydrazonato ligand, whereas the trinuclear complex 192+ adopts a syn conformation with an Fe-Fe-Fe angle of 180°. Other salient features of these structures are the long Fe-Cipso bond distances and the slight cyclohexadienyl character at the coordinated C6 ring, with a folding angle of 7.4° and 7.0° for 16+ and 19 2+, respectively.
- Manzur, Carolina,Zuniga, Cesar,Millan, Lorena,Fuentealba, Mauricio,Mata, Jose A.,Hamon, Jean-Rene,Carrillo, David
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- A new synthesis and electrochemistry of 1,1′-bis(β-hydroxyethyl)ferrocene
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The preparation of 1,1′-bis(β-hydroxyethyl)ferrocene (1) by oxidation of 1,1′-divinylferrocene is described. Compound 1 has been characterized by 1H and 13C{1H} NMR, and cyclic voltammetry. The electrochemical data are com
- Barry, Kevin P.,Nataro, Chip
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- A New Class of C2-Symmetric Chiral Cyclopentadienyl Ligand Derived from Ferrocene Scaffold: Design, Synthesis and Application
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A new class of C2-symmetric, chiral cyclopentadienyl ligand based on planar chiral ferrocene backbone was developed. A series of its corresponding rhodium(I), iridium(I), and ruthenium(II) complexes were prepared as well. In addition, the rhodium(I) complexes were evaluated in the asymmetric catalytic intramolecular amidoarylation of olefin-tethered benzamides via C?H activation.
- Liang, Hao,Vasamsetty, Laxmaiah,Li, Teng,Jiang, Jijun,Pang, Xingying,Wang, Jun
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- New Polyaza Tris-ferrocene and Tris-2,2'-bipyridyl Macrobicyclic Cryptand Molecules. Isolation of Homo- and Hetero-polymetallic Zinc(II) and Copper(I) Cryptates containing Externally Coordinated Ruthenium(II) Cations
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New multisite ligands containing either three peripherally linked ferrocene redox centres (L1,L3) or three externally orientated 2,2'-bipyridyl transition metal recognition sites (L2,L4) have been prepared and t
- Beer, Paul D.,Kocian, Oldrich,Mortimer, Roger J.,Spencer, Paul
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- Structural influences on the electrochemistry of 1,10-di(hydroxyalkyl) ferrocenes. Structure of [Fe{h5-C5H4eCH(OH)e(CH2)3OH}2]
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Abstract A series of 1,1'-di(hydroxyalkyl)ferrocenes, [Fc'{(CH 2)nOH}2], with n = 1 (1), 2 (2), 3 (3) and 4 (4) and Fc' = Fe(η5-C5H4)2, was synthesized. The electrochemistry of the di(hydroxyalkyl)ferrocenes was studied by cyclic voltammetry in CH2Cl2/0.1 M [N nBu4][PF6] utilizing a glassy carbon working electrode. The ferrocenyl group showed reversible electrochemistry with the formal reduction potential, Eo' , inversely proportional to alkyl chain length and approximately 59 mV smaller than those of the corresponding mono(hydroxyalkyl)ferrocenes derivatives [Fc(CH2)mOH] with m = 1 (1m), 2 (2m), 3 (3m), and 4 (4m) and Fc = Fe(η5-C 5H5)(η5-C5H4 -). The tetraalcohol [Fc'{CH(OH)(CH2)3OH} 2], 5, possessing four OH functionalities, two in the terminal positions and two more, one on each of the two α-C relative to the ferrocenyl (Fc' for dialcohols or Fc for monosubstituted derivatives) group, was isolated as a side product during the synthesis of 4. The formal reduction potential of 5 was Eo' = -24 mV vs. FcH/FcH+ and closely approached Eo' of [FcCH(OH)CH3] (Eo' = -11 mV), [Fc'{CH(OH)CH3}2] (-21 mV) and 1 (0.00 mV vs. FcH/ FcH+). The single crystal X-ray structure of the tetraalcohol 5 (Z = 8, orthorhombic, space group Pbca) was also solved.
- Claus, Ron,Lewtak, Jan P.,Muller, Theunis J.,Swarts, Jannie C.
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- An Enantioselective Oxidative C-H/C-H Cross-Coupling Reaction: Highly Efficient Method to Prepare Planar Chiral Ferrocenes
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A Pd-catalyzed, asymmetric oxidative cross-coupling reaction between ferrocenes and heteroarenes is described. The process, which takes place via a twofold C-H bond activation pathway, proceeds with modest to high efficiencies (36-86%) and high levels of regio- and enantioselectivity (95-99% ee). In the reaction, air oxygen serves as a green oxidant and excess amounts of the coupling partners are not required. The process is the first example of a catalytic asymmetric biaryl coupling reaction that occurs via double C-H bond activation. Finally, the generated coupling products can be readily transformed into chiral ligands and catalysts.
- Gao, De-Wei,Gu, Qing,You, Shu-Li
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- Synthesis, molecular structure and properties of a ferrocene-based difluoropyrrolo-oxaborole derivative
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Reaction of 1,1′-ferrocenedicarbonyl chloride with 3-ethyl-2,4-dimethylpyrrole in DCM produced the half-way product, namely, the ferrocene bis(2-ketopyrrole) derivative 2 and not the expected bis(dipyrromethene) compound. The 2-ketopyrrole compound readily reacted with BF3·Et2O to produce the bis(difluoropyrrolo)-oxaborole compound, FBF, as a red/brown solid which was characterised by X-ray crystallography. 57Fe M?ssbauer spectra for 2 and FBF were consistent with low-spin iron(II) (d6) ferrocene derivatives. A cyclic voltammogram for 2 in acetonitrile revealed a reversible wave at +0.31 V vs. Fc+/Fc (ferrocene-based) and an irreversible wave at -2.38 V vs. Fc+/Fc (ketopyrrole-based). The electrochemical behaviour is severely perturbed by the chelation of the BF2 groups. Alterations to the electronic properties of 2 by formation of FBF are also evident in the absorption profiles. DFT calculations [B3PW91, 6-31G(3df)] support the observed changes in the electrochemistry findings and the M?ssbauer spectroscopic data. Reaction of 1,1′-ferrocenedicarbonyl chloride with 3-ethyl-2,4-dimethylpyrrole produces the bis(ketopyrrole) compound. Chelation of BF2 to the ketopyrrole units forms the difluoropyrrolo-oxaborole.
- Benniston, Andrew C.,Sirbu, Dumitru,Turta, Constantin,Probert, Michael R.,Clegg, William
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- Triggered Metal Ion Release and Oxidation: Ferrocene as a Mechanophore in Polymers
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The introduction of mechanophores into polymers makes it possible to transduce mechanical forces into chemical reactions that can be used to impart functions such as self-healing, catalytic activity, and mechanochromic response. Here, an example of mechanically induced metal ion release from a polymer is reported. Ferrocene (Fc) was incorporated as an iron ion releasing mechanophore into poly(methyl acrylate)s (PMAs) and polyurethanes (PUs). Sonication triggered the preferential cleavage of the polymers at the Fc units over other bonds, as shown by a kinetic study of the molar mass distribution of the cleaved Fc-containing and Fc-free reference polymers. The released and oxidized iron ions can be detected with KSCN to generate the red-colored [Fe(SCN)n(H2O)6?n)](3?n)+ complex or reacted with K4[Fe(CN)6] to afford Prussian blue.
- Di Giannantonio, Michela,Ayer, Mathieu A.,Verde-Sesto, Ester,Lattuada, Marco,Weder, Christoph,Fromm, Katharina M.
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- Some insights into the gold-catalysed A3-coupling reaction
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A series of cyclometallated and functionalised NHC gold(I) and gold(III) complexes, many of which feature chiral ligands, and their application to A3-coupling reactions is presented. Gold(III) complexes were found to be particularly effective catalysts for the coupling in a range of solvents, however no asymmetric induction was obtained when using chiral gold complexes and the rate of product formation was found to be similar even when using different ligand systems. In-situ NMR analysis of these reactions indicates that decomposition of the catalyst occurs during the course of the reaction while TEM studies revealed the presence of gold nanoparticles in crude reaction mixtures. Taken together these data suggest that the gold nanoparticles, rather than the intact gold complexes, could be the catalytically active species, and if so this may have significant implications for other gold-catalysed systems.
- Price, Gregory A.,Brisdon, Alan K.,Randall, Simon,Lewis, Edward,Whittaker, Daniel M.,Pritchard, Robin G.,Muryn, Chris A.,Flower, Kevin R.,Quayle, Peter
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- ThDione: A Powerful Electron-Withdrawing Moiety for Push–Pull Molecules
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A series of new push–pull chromophores based on a combined cyclopenta[c]thiophene-4,6-dione (ThDione) acceptor, N,N-dimethylaniline, N-piperidinylthiophene or ferrocene donors, and ethylene or buta-1,3-dienylene π-linkers has been designed and synthesized. Utilizing one or two ThDione acceptors afforded linear or branched push–pull molecules. Experimental and theoretical study of their fundamental properties revealed thermal robustness up to 260 °C, a electrochemical/optical HOMO–LUMO gap that is tunable within the range of 1.47–2.19/1.99–2.39 eV, and thorough elucidation of structure–property relationships. Compared to currently available portfolio of heterocyclic electron-withdrawing units, ThDione proved to be a powerful and versatile acceptor unit. It imparts significant intramolecular charge transfer and polarizes the π-system, which results in enhanced (non)linear optical response.
- Bure?, Filip,Jedryka, Jaroslaw,Kityk, Iwan V.,Klikar, Milan,Ludwig, Miroslav,Novotná, Eva,Ozga, Katarzyna,Pytela, Old?ich
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- Mono and difunctionalisation of chiral ferrocenyl bis-acetals. X-Ray crystal structure of bis-1,1′-[(2S, 4S)-(hydroxymethyl)-2-dioxane1,3]-ferrocene
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The chiral 1,1′-bis-acetals, bis-1,1′-[(2S, 4S)-(hydroxymethyl)-2-dioxane1,3]-ferrocene (3) and 1,1′-bis-1,1′-[(2S, 4S)-(methoxymethyl)-2-dioxane1,3]-ferrocene (4) were synthesized. (3) was crystallographically characterised. The ortholithiation of (4) was studied in various conditions. Fair yields of monosubstituted compounds could be obtained with a complete regioselectivity in favor of the 2 position but the diastereoselectivities were moderate (up to 35%). Some disubstituted compounds can be isolated but in low yields (up to 8%). The regioselectivity is complete in favor of the 2,2′-disubstituted isomer. Only the diastereoisomer with two opposite planar chiralities is observed.
- Iftime, Gabriel,Daran, Jean-Claude,Manoury, Eric,Balavoine, Gilbert G.A.
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- Synthesis of ferrocene/chitosan-AgNPs films and application in plasmonic color-switching and antimicrobial materials
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As a new dialdehyde cross-linking agent, Ferrocene-1,1′-dicarbaldehyde (FcDa) was synthesized and used firstly for chitosan (FcDa/CS) by our group. Silver nanoparticles (AgNPs) were formed in situ by doping the AgNO3 solution into the FcDa/CS film forming solution without adding other reductant because that the Fe(II) of ferrocene has good reducibility. A series of ferrocene-1,1′-dicarbaldehyde)/Chitosan-AgNPs (FcDa/CS-AgNPs) films was prepared by solution casting. The basic structures of FcDa/CS and FcDa/CS-AgNPs were examined by using Fourier transform infrared (FT-IR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and UV–vis spectrophotometer. The FcDa/CS is a layered, rigid and double network structure. According to the XPS energy spectrum data, the energy spectrum shift of ferrocene and the generation of Schiff-base can be observed, which show that FcDa can reduce Ag+ to Ag. Depending on the difference of AgNO3 concentration, the aggregation degree, quantity and size of the obtained AgNPs on the surface of the film were different. By adjusting acid-base environment for realizing the deprotonation/protonation of amino group, the prepared film exhibited the plasmonic color-switching properties from reddish brown to golden yellow. The surface plasmon resonance (SPR) peak of the films under different pH environments shifted from 430 to 464 nm. The cubic silver structure was also observed on the surface micro morphology after the color change of the films. These phenomenons confirmed that this color change was the plasmonic color-switching properties of FcDa/CS-AgNPs films. Additionally, the inhibition zone experiment showed that the FcDa/CS-AgNPs films had antimicrobial activity against Escherichia coli and Staphylococcus aureus. The FcDa/CS-AgNPs films have potential application in smart plasmonic color-switching and antimicrobial materials.
- Chen, Lianmei,Du, Xiaofei,Guo, Xiaoqiang,Jiang, Haiyan,Kang, Tairan
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- Site-selective cation-π interaction as a way of selective recognition of the caesium cation using sumanene-functionalized ferrocenes
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The first sumanene-ferrocene probes for efficient and selective caesium cation (Cs+) recognition are reported. The working mechanism of the sumanene moiety as the sensing unit was based on the site-selective cation-π interaction in its neutral state. The interactions with Cs+ were characterized by high association constant values together with low limits of detection.
- Kasprzak, Artur,Sakurai, Hidehiro
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supporting information
p. 17147 - 17152
(2019/12/04)
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- Ferrocene derivative containing carbon-carbon and carbon-nitrogen double-bond long-chain conjugated system and preparation method and application of ferrocene derivative
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The invention discloses a ferrocene derivative containing a carbon-carbon and carbon-nitrogen double-bond long-chain conjugated system and a preparation method and application of the ferrocene derivative. The structural formula of the ferrocene derivative is as shown in the specification. The ferrocene derivative is good in second-order and third-order non-linear optical activity, and can be used as a photoelectric material.
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Paragraph 0105
(2016/10/09)
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- A double-allyl three-carbon ester ferrocene monomer and its preparation method
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The invention relates to a diallyl tri-carbonic ester ferrocene monomer and a preparation method thereof. The preparation method is characterized by using 1,1'-bis(1-methoxy-3-butenyl) ferrocene and 1-methoxy-1-(trimethylsiloxy)-2-methyl-1-propylene as raw materials and dropwise adding a boron trifluoride diethyl ether complex at a low temperature, thus obtaining a 1,1'-bis[1-(1-methoxycarbonyl-1-methyl-ethyl)-3-allylbutyl]ferrocene compound. Trimethyl carbonate ferrocene symmetrically replaced by diallyl not only can be used for melt polycondensation of polyester but also has the capability, endowed by double bonds, of participating in polymerization reaction, therefore, trimethyl carbonate ferrocene is a novel ferrocenyl monomer.
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Paragraph 0040-0044
(2017/06/02)
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- The first application of C2-symmetric ferrocenyl phosphinite ligands for rhodium-catalyzed asymmetric transfer hydrogenation of various ketones
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Homogeneous catalysis has been responsible for many major recent developments in synthetic organic chemistry. The combined use of organometallic and coordination chemistry has produced a number of new and powerful synthetic methods for important classes of compounds in general and for optically active substances in particular. For this aim, a new class of chiral modular C2-symmetric ferrocenyl phosphinite ligands has been prepared in good yields by using the inexpensive 1,1′-ferrocenedicarboxyaldehyde and various ferrocene based-amino alcohols as starting materials, and applied in the rhodium(I)-catalyzed asymmetric transfer hydrogenation (ATH) of aromatic ketones to give corresponding secondary alcohols with excellent enantioselectivities and reactivities using isoPrOH as the hydrogen source (up to 99% conversion and 99% ee). The substituents on the backbone of the ligands are found to exhibit a remarkable effect on both the activity and % ee. The structures of these ligands and their complexes have been elucidated by a combination of multinuclear NMR spectroscopy, IR spectroscopy and elemental analysis.
- Ak, Bünyamin,Aydemir, Murat,Durap, Feyyaz,Meri?, Nermin,Baysal, Akin
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- Highly efficient iridium catalysts based on C2-symmetric ferrocenyl phosphinite ligands for asymmetric transfer hydrogenations of aromatic ketones
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A series of chiral modular C2-symmetric ferrocenyl phosphinite ligands have been synthesized in good yields by using 1,1′-ferrocenedicarboxyaldehyde and various amino alcohols as starting materials, and applied in the iridium(III)-catalyzed asymmetric transfer hydrogenations of aromatic ketones to give the corresponding secondary alcohols with good enantioselectivities and reactivities using 2-propanol as the hydrogen source (up to 98% ee and 99% conversion). The substituents on the backbone of the ligands were found to have a significant effect on both the activity and enantiomeric excess. The structures of these complexes have been clarified by a combination of multinuclear NMR spectroscopy, IR spectroscopy, and elemental analysis.
- Ak, Bünyamin,Aydemir, Murat,Durap, Feyyaz,Meri?, Nermin,Elma, Duygu,Baysal, Akin
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p. 1307 - 1313
(2015/11/25)
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- Aminomethyl-substituted ferrocenes and derivatives: Straightforward synthetic routes, structural characterization, and electrochemical analysis
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A variety of aminomethyl-substituted ferrocenes and the parent compounds (iminomethyl)ferrocenes, azaferrocenophanes, and diferrocenylamines can be selectively synthesized from reductive amination of 1,1′-diformylferrocene or formylferrocene. The optimized one- or two-step reactions have delivered 13 new compounds, isolated in 65-97% yields, which include tertiary (ferrocenylmethyl)amines and azaferrocenophanes by using NaBH(OAc)3 as a mild reducing agent and (iminomethyl)ferrocenes and secondary (ferrocenylmethyl)amines by using LiAlH4. X-ray structures of representative members of these ferrocene derivative families have evidenced the preferred conformation adopted by ferrocene backbones, in which surprisingly the steric hindrance is apparently not systematically minimized. 15N NMR measurements on aminomethyl-substituted ferrocenes and derivatives are provided for the first time, establishing benchmark values ranging from -330 to -305 ppm (nitromethane δ 0 ppm). The cyclic voltammetry of these species evidences two clearly distinct oxidation potentials related to the iron(II) center and the amino function. These aminomethyl-substituted ferrocenes are potentially valuable for further ortho-directed functionalization of ferrocene.
- Dwadnia, Nejib,Allouch, Fatima,Pirio, Nadine,Roger, Julien,Cattey, Helene,Fournier, Sophie,Penouilh, Marie-Josee,Devillers, Charles H.,Lucas, Dominique,Naoufal, Daoud,Ben Salem, Ridha,Hierso, Jean-Cyrille
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p. 5784 - 5797
(2013/11/19)
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- Bi-functionalised metallocenes use for marking biological molecules
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The invention relates to bi-functionalised metallocenes of general formula (I) where Me=a transition metal, preferably chosen from Fe, Ru and Os, Y and Z, when identical are selected from —(CH2)n—O—, (CH2)—O—[(CH2)2—O]P— and —(CH2)q—CONH—(CH2)r—O—, or Y=—(CH2)S—NH— and Z=—(CH2)t—COO—, n=a whole number from 3 to 6 inclusive, p=a whole number from 1 to 4 inclusive, q=a whole number from 0 to 2 inclusive, r=a whole number from 0 to 2 inclusive, s=a whole number from 2 to 5 inclusive, t=a whole number from 3 to 6 inclusive, R and R′=H atoms or are protective groups used in oligonucleotide and peptide synthesis, where at least one of R or R′ is protective group used in oligonucleotide and peptide synthesis and R and R′ are as defined below: (i) when Z and Y are selected from (CH2)n—O—, —(CH2)—O—[(CH2)2—O]p— and —(CH2)q—CONH—(CH2)r—O—, then R and R′ are protective groups used in oligonucleotide synthesis and R is a group which can leave a free OH group after deprotection, preferably a photolabile group such as monomethroxythoxytrityl, dimethoxytrityl, t-butyldimethylsilyl, acetyl or trifluroacetyl, and R′ is a phosphorylated group which can react with a free OH, preferably a phosphodiester, phosphoramidite or H-phosphonate and (ii) when Y=—(CH2)n—NH— and Z=—(CH2)t—COO—, then R is a protective group used in the synthesis of peptides and is an amino-protecting group, preferably 9-fluorenyloxycarbonyl, t-butoxycarbonyl or benzyloxycarbonyl and R′=H. The above is applied in marking.
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Page/Page column 11
(2010/02/10)
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- Efficient regio- and diastereo-controlled synthesis of 1,1′- and 1,1′,2,2′-functionalised ferrocenes and the formation of 2-oxa[3]ferrocenophanes
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The synthesis of a C2 symmetric 1,1′ ,2,2′-tetrasubstituted ferrocene system was discussed. The route involved the reduction of ferrocenyl carbonyl compounds which gave access to a range of alcohols, alkenes, alkanes, ethers, and 2-oxa[3]ferrocenophanes depending on the precise conditions used. The loss of optical activity of 1,1′-bis(hydroxymethyl)ferrocenes and 1,1′-bis(hydroxymethyl)ruthenocenes, which had been prepared by asymmetric reduction, was demonstrated in an acidic medium by extensive 1H NMR studies.
- Carroll, Michael A.,White, Andrew J.P.,Widdowson, David A.,Williams, David J.
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p. 1551 - 1557
(2008/10/08)
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- Selective functionalization of the 1′-position in ferrocenecarbaldehyde
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An efficient and selective new method for the preparation of unsymmetrical 1,1′-disubstituted ferrocenes by a one-pot procedure, starting from ferrocenecarbaldehyde, is disclosed.
- Iftime, Gabriel,Moreau-Bossuet, Caroline,Manoury, Eric,Balavoine, Gilbert G. A.
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p. 527 - 528
(2008/10/09)
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- The lithiation of ferrocene and ruthenocene: A retraction and an improvement
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We reported in 1993 an efficient synthesis of ferrocene and ruthenocene mono-and dialdehydes which suggested the first truly specific monolithiation of these two metallocenes (U.T. Mueller-Westerhoff, Z. Yang and G. Ingram, J. Organomet. Chem., 463 (1993) 163). Unfortunately, these results were based on inappropriate experimental methods. We have now meticulously analyzed a wide spread of reaction conditions and have concluded that an effective monolithiation of ferrocene and of ruthenocene is possible, but not under the previously described reaction conditions.
- Sanders, Richard,Mueller-Westerhoff, Ulrich T.
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p. 219 - 224
(2007/10/03)
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- A simple synthesis of metallocene aldehydes from lithiometallocenes and N,N-dimethylformamide: ferrocene and ruthenocene aldehydes and 1,1'-dialdehydes
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Lithioferrocene, 1,1'-dilithioferrocene, lithioruthenocene and 1,1'-dilithioruthenocene all react with N,N-dimethylformamide in diethyl ether to produce the respective aldehydes.The lithiation of the two metallocenes can be steered to maximize the formation of only one of the two aldehydes by choosing either n-butyllithium in the presence of tetramethylethylenediamine (TMEDA) or t-butyllithium (tBuLi) as the metallating reagent: ferrocene mono-aldehydes or 1,1'-dialdehydes are formed with good yields (91percent and 85percent respectively, based on ferrocene), lower yields (50percent) of ruthenocene-1,1'-dialdehyde were obtained under the standard conditions, because the 1,3,1'-trialdehyde also formed in significant (19percent) amounts.Monolithiation by nBuLi and the formation of the ruthenocene monoaldehyde (yield, 66percent) are favoured when TMEDA is used in only catalytic amounts; lithiation of ruthenocene by tBuLi selectively leads to monolithioruthenocene and the mono-aldehyde (yield, 91percent).The products are easily purified by column chromatography.The simplicity and the high yield of these reactions make them much more desirable than the previously known multistep procedures.
- Mueller-Westerhoff, Ulrich T.,Yang, Zheng,Ingram, Georg
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p. 163 - 168
(2007/10/02)
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