Asymmetric Induction of Chiral 1,1'-Bis(oxazolinyl)ferrocenes as Ligands in Metal-Catalyzed Cyclopropanation and Diels-Alder Reactions

Four chiral 1,1?bis(oxazolinyl)ferrocenes(1a-1d) have been prepared and used as ligands in the copper catalyzed asymmetric cyclopropanation of styrene with ethyl diazoacetate (EDA) and the magnesium catalyzed Diels-Alder reaction between 3-acryloyl-2-oxazolidinone and cyclopentadiene. Enantioselectivities up to 24% and 41%, respectively, for cyclopropanation and Diels-Alder reaction were observed.

Detection of Oxidized Ferrocenes by LC-MS with Electrospray Ionization Using Picric Acid as the Counter Ion

Ferrocene is an organometallic compound that readily undergoes oxidation in atmosphere under acidic conditions. However, because of its diamagnetic nature, ferrocene does not lend itself to structural analysis by nuclear magnetic resonance (NMR) spectroscopy. In this work, the oxidation of ferrocene and several of its derivatives were analyzed by liquid chromatography-mass spectrometry (LC-MS). An electrospray ionization (ESI) source was used, with picrate serving as the counter ion. This method is particularly effective for studying oxidation of ferrocenes because their reactivity toward oxygen under ambient conditions is low.

Construction of Planar Chiral Ferrocenes by Cobalt-Catalyzed Enantioselective C–H Acyloxylation Enabled by Dual Ligands

Oxy-substituted planar chiral ferrocenes are of great importance in asymmetric synthesis and pharmaceuticals.However,enantioselective C–H activation of ferrocenes that form C–O bonds remains a huge challenge and has not yet been reported.Herein,the asymmetric synthesis of oxy-substituted planar chiral ferrocenes is achieved by cobalt-catalyzed enantioselective dehydrogenative C–H acyloxylation.The use of a dual-ligand system consisting of a chiral salicyloxazoline(Salox)ligand and a neutral phosphine oxide ligand,which is oxidized in situ from the corresponding phosphine,resulted in good yield(up to 83%)and excellent enantioselectivity(90–99%ee).The utility of this unprecedented protocol is highlighted by its versatile synthetic transformations.

Synthesis of planar chiral isoquinolinone-fused ferrocenes through palladium-catalyzed C-H functionalization reaction

(S,S)-Me-BI-DIME/Pd(0)-catalyzed ennantioselective C-H functionalization of N-ferrocenyl o-bromobenzanilides has been realized,affording isoquinolinone-fused ferrocenes with up to 97% ee.The products can be transformed into planar chiral ferrocenyl monophosphines,which demonstrate their preliminary application.

Rhodium-Catalyzed Pyridine-Assisted C-H Arylation for the Synthesis of Planar Chiral Ferrocenes

Planar chiral ferrocenes are widely applied in organic synthesis,materials science,and medicinal chemistry,but their synthesis is not trivial.Herein,a highly efficient synthesis of planar chiral ferrocene-based pyridine derivatives via Rh(I)-catalyzed direct coupling of pyridylferrocenes with aryl halides was developed.Good yields and excellent enantioselectivity(95–>99%ee)are obtained for a wide range of substrates.The compatibility of gram-scale synthesis and relatively low catalyst loading(down to 1 mol%based on[Rh])enhance the practicality of the current method.The generated coupling products can be readily transformed into chiral ligands.Mechanistic studies suggest that the C–H bond cleavage of pyridylferrocene may be a reversible step and not the rate-determining step.Significant nonlinear effects indicate the existence of multiple metals or ligands in the active catalyst.

Mushroom Pulp Tissue-Based Membrane-Ferrocene-Modified L-Tyrosine Biosensor

A new approach for assembling amperometric mushroom pulp tissue based membrane electrode for determination of L tyrosine analysis is proposed. Ferrocene is used as a mediator of electron transfer between tyrosinase in mushroom tissue and a graphite electrode. The optimal operation conditions are studied. The linear response range of the biosensor is 2 0×10 -4 to 4 5×10 -3 mol·L -1 with response time of less than 5 min and lifetime of at least 30 d. The biosensor can be applied to practical sample analysis.

Synthesis and Structure of a Titanocene-ferrocenyl Complex

A titanocene-ferrocenyl complex, （5-ferrocenyl-2-hydroxybenzenecarboxylato- O,O′）-bis（methylcyclopentadienyl）titanium（IV） 4, and an unexpected ionic complex, [C7H8NO3]- [（C5H5）Fe（C5H4）SO3]·H2O3 were synthesized and characterized by IR, ^1H NMR and elemental analysis. Compound 3 is of triclinic, space group P1 with a = 5.954（2）, b = 13.208（5）, c = 13.252（5） A, α = 60.993（7）,β = 84.342（8）,γ = 86.933（8）°, Z = 2, V = 906.8（6）A^3, Dc = 1.601 g/cm^3, μ（MoKα） = 0.987 mm^-1, F（000） = 452, the final R = 0.0647 and wR = 0.1333 for 2311 observed reflections （I 〉 2σ（I））. Compound 4 belongs to the monoclinic system, space group P2 1/c with α = 14.3310（9）, b = 12.5065（8）, c = 12.9406（10） A, β = 95.101（4）°, Z = 4, V = 2310.2（3） A^3, Dc = 1.513 g/cm^3, μ（MoKα） = 1.004 mm^-1, F（000） = 1088, the final R = 0.0461 and wR = 0.1048 for 2112 observed reflections （1 〉 2σ（I））.

Sensitive Voltammetric Determination of Captopril Using a Carbon Paste Electrode Modified with Nano-TiO_2/Ferrocene Carboxylic Acid

A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.

Experimental study on gas explosion suppression based on ferrocene

In order to study the gas explosion suppression performance based on ferrocene, the self-constructed experimental facility was used to accomplish the experiment of gas explosion suppression. By means of thermogravimetric analysis, the thermal characteristics of ferrocene have been gotten and the gas explosion suppression mechanism of ferrocene has been analyzed. The results show that ferrocene had good effects on gas explosion suppression, and the explosion pressure and flame propagation speed declined obviously. When ferrocene concentration is 0.08 g/L and methane volume concentration is 9.5%, the maximum explosion overpressure and maximum flame propagation speed of methane-air respectively decreased by about 59.5% and 19.6%, respectively. TG and DSC curves showed that the mass loss of ferrocene consists of two processes, which are sublimation and lattice fracture. The temperature of mass loss ranged from 128 ℃ to 230 ℃. The results showed profoundly theoretical significance to gas explosion suppression by ferrocene in coal mines.

Glucose Biosensor Based on Carbon/PVC-COOH/Ferrocene Composite with Covalently Immobilized Enzyme

A carbon/PVC-COOH/ferrocene composite electrode used for the determination of glucose has been prepared. The ferrocene acted as mediator was incorporated into the PVC-COOH polymer and the leakage could be prevented. The presence of carboxyl groups on the electrode surface allowed immobilizing enzyme via EDC and NHS. The ratio of PVC-COOH to graphite powder （w/w） has been studied. Amperometric determination of glucose has been performed at potential of 0.30 V vs SCE. The response time was 〈 15 s. The linear response range was of 0.1-20 mmol/L with a detection limit of 48μmol/L.

Novel organometallic aromatic polyester based on ferrocene

A novel polyester containing ferrocenyl was prepared by low-temperature interface polycondensation of 1,1'-ferrocenedicarboxylic acid chloride with 4-(4-hydroxyphenyl)-2,3-phthalazin-1-one(DHPZ),which is a twisted non-coplanar heterocyclic bisphenol-like monomer.The newly generated polymer was evaluated based on characterization of its solubility,viscosity measurements,elemental analysis,FTIR spectroscopy,differential scanning calorimetric and thermogravimetric studies.

Synthesis and Characterization of Ferrocenyl Substituted Styryl Octasilsesquioxane

4-（2-Ferrocenylethenyl）-phenyl-POSS Fc-CH=CH-C6H6-（C5H9）7Si8O12 （FEPS, Fc： ferrocene）, containing metal and C=C double bond, was firstly synthesized as a mixture of E/Z isomers by the Wittig reaction. The chemical structure of FEPS was characterized by FTIR, ^1H-, ^13C and ^29Si- NMR.

Preparation and chiral recognitio of a novel chiral stationary phase for HPLC,based on mono(6~A-N-1-(2-hydroxyl)-phenylethylimino-6~A-deoxy)-β-cyclodextrin and covalently bonded silica gel

A novel chiral stationary phase （CSP） was prepared by immobilizing mono（6A-N-1-（2-hydroxyl）-phenylethylimino-6A- deoxy）-β-cyclodextrin onto the surface of silica gel via a longer spacer. This chiral stationary phase exhibited good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.

CH_4 oxidation to oxygenates with N_2O over iron-containing Y zeolites:Effect of preparation

Developing effective iron-incorporated zeolites and determining their active centers for the direct oxidation of CH_4 to oxygenates have remained challenging topics so far.In this paper,we successfully prepare the highly-dispersed iron supported Y zeolites by a facile solid-state ion-exchange method with ferrocene,which was conducted under water-free conditions followed by a series of calcination.Moreover,extra-framework dinuclear Fe^(2+)complexes are identified as so-called activeα-iron sites on zeolites.ICP-OES,N_2 adsorption–desorption test,X-ray diffraction,solid-state^(27)Al NMR,N_2O titration,TEM,EPR and^(57)Fe M?ssbauer spectra were carried out to characterize properties of sample structure,acid sites,as well as the supported iron species.Characterization results indicate that high-temperature treatments have no effect on the typical structure feature of zeolites.Compared with catalysts synthesized by conventional impregnation,the samples prepared by the facile approach possess abundant dinuclear Fe^(2+)complexes but no Fe_2O_3 bulks and show weak acidity.These lead to a higher oxygenate selectivity in CH_4 oxidation to oxygenates.Remarkably,the oxygenate(HCHO and CH_3OH)selectivity of 6.5% at 375°C can be eventually obtained.

Studies on Lead(Ⅱ) Complexes of Ferrocenylaldehyde Aroylhydrazones

The complexes of four ferrocenylaldehyde aroylhydrazones with lead(Ⅱ) were synthesized and characterized. Their compositions, bonding forms and properties were researched by means of elemental analysis, IR, UV Vis, 1H NMR spectra, thermal analysis and molar conductance. The free ligands which existed in the keto form coordinated to lead(Ⅱ) in the enol form to form neutral complexes. The molar ratio of the ligand to lead(Ⅱ) is 2∶1 and the thermal stability of the complex is higher than that of the corresponding ligand because of the formation of the stable chelate ring. The ligands and the complexes are all non electrolytes.

Ferrocenyl building block constructing porous organic polymer for gas capture and methyl violet adsorption

Ferrocene-based porous organic polymer(FcPOP) was constructed with ferrocene and porphyrin derivatives as building blocks via Schiff-base coupling. FcPOP was well characterized, and exhibited good thermal stability, high porosity, microporous structure, and homogeneous pore size distribution. Ferrocene blocks with highly electron-rich characteristics endowed Fc POP with excellent adsorption capacity of CO2 and methyl violet. The kinetic study indicated adsorption of methyl violet onto FcPOP mainly complied with pesudo-second order model. The maximum adsorption capacity of FcPOP derived from Langmuir isotherm model reached up to 516 mg/g. More importantly, FcPOP could be easily regenerated and repeatedly employed for removal of methyl violet with high efficiency. Overall, FcPOP in the present study highlighted prospective applications in the field of gas capture and dyeing wastewater treatment.

Friedel-Crafts Acylation of Ferrocene Catalyzed by Solid Superacid,Silica-supported Polytrifluoromethanesulfosiloxane

Solid superacid, silica-supported polytrifluoromethanesulfosiloxane (SiO2-Si-SCF3) wasfirstly used in the Friedel-Crafts acylation of ferrocene as a novel catalyst. IR spectra, WAXD andspecific surface area of the superacid SiO2-Si-SCF3 were also investigated.

1, 1'—BIS (BENZYLSELENO) FERROCENE PLATINUM COMPLEX AS HYDROSlLYLATION CATALYST FOR OLEFINS

1, 1'--Bis(benzylseleno)ferrocene and its platinum complex were synthesized. It was found that the platinum complex was efficient catalyst for the hydrosilylation of olefins with triethoxysilane.

Application of the Reactions of Ferrocene（Ⅰ） Salts with Bis［dicarbonyl（η￣5－cyclopentadienyl）iron］ and Bis［dicarbonyl（η￣4－butadiene）cobalt］ Complexesto Organic Synthesis

omplexes[(η￣5-C_5H_5)Fe (CO)_2L]￣+BF(Ⅰ)[L=PPh_3,P(OPH)_3,P(OC_2H_5)_3,pyridine, 3-acetyl-pyridine, 4-methyl-pyridine, phenyl cyanide, quinoline] and[(η￣4-C_4H_6)Co(CO)_2L]￣+BF(Ⅱ)[L=PPh_3,P(OPH)_3,P(OC_2H_5)_3],were respec-tively produced in the reactions of[(η￣5-C_5H_5)Fe (CO)_2 ]_2 and [ (η￣4-C_4H_5 )Co (CO)_2]_2with Cp_2FeBF_4 in the presence of the ligands. Some characteristics of these reac-tions were discussed and all the complexes were identified by iR and ￣1H NMR spec-troscopy. These complexes are air-stable and the preparative metliods are simple.

Synthesis and Crystal Structure of Dibromo [1,1′- bis(diphenylphosphino)ferrocene]cadmium(II)

The title complex Cd(dppf)Br2 (dppf=1,1′-bis(diphenylphosphino)ferrocene) (C34H28Br2 P2CdFe, Mr=826.57) has been synthesized and characterized by X-ray diffraction. The crystal is in monoclinic, space group C2/c with cell parameters: a = 34.285(4), b = 10.050(1), c = 18.697(2) ? β= 98.843(3)? V = 6366(1)3, Z = 8, Dc = 1.725g/cm3, (MoKa) = 0.71073 ? =3.757mm-1, F(000)=3248. The final refinement with 4469 observed reflections and 361 parameters gave R=0.0584 and wR=0.1522. The 1,1′-bis(diphenylphosphino)ferrocene group is connected to the Cd atom as a bidentate ligand. The Cd atom has a distorted tetrahedral coordination.