Reaction in Dry Media: Silica Gel Supported Ferric Chloride Catalyzed Synthesis of 1,8-Dioxo-octahydroxanthene Derivatives

Herein, we describe a green procedure for the one-pot preparation of 1,8-dioxo-octahydroxanthene derivatives by condensation of dimedone and substituted benzaldehydes in the presence of FeCl ₃ -SiO ₂ as an efficient and heterogeneous catalyst under microwave irradiation and thermal conditions. This method has the advantages of high yields, cleaner reactions, efficient and cost-effective method, simple methodology, short reaction times, easy workup, and greener conditions.     

A modified reaction for the preparation of amidoalkyl naphthols

An efficient synthesis of amidoalkyl naphthols using FeCl₃·SiO₂ as a heterogeneous catalyst is described. This thermal solvent-free procedure offers advantages such as shorter reaction times, simple work-up, excellent yields, and recovery and reusability of the catalyst.     

[Bmim]Cl/FeCl3离子液体催化α-生育酚与β-D-五乙酰葡萄糖的糖基化反应

以[Bmim]Cl/FeCl₃(三氯化铁/氯化丁基甲基咪唑)离子液体作为反应介质和催化剂, 考察了离子液体的酸度、反应温度及反应时间对α-生育酚与β-D-五乙酰吡喃型葡萄糖糖基化反应的影响. 结果表明, 离子液体的催化活性与其酸强度密切相关, 离子液体的酸性越强, 其对此糖基化反应催化活性越高. 在FeCl₃与[Bmim]Cl物质的量比为2的[Bmim]Cl/FeCl₃离子液中, α-生育酚与β-D-五乙酰吡喃型葡萄糖在45 ℃下反应3 h, 可以得到较高的转化率, α-生育酚的转化率最高可达70.2%. 同有机溶剂作为反应介质相比, 反应条件温和, 反应时间短, 室温离子液体具有更好的催化活性, 所得产物与离子液体不溶, 便于分离, 催化体系可循环使用, 且对环境友好.     

Improved facile synthesis of α-amino phosphonates by the reaction of α-amido sulfones with dialkyl trimethyl silyl phosphites catalyzed by Fe(III) chloride

An improved efficient synthesis of α-amino phosphonates has been discovered by the reaction of N-benzyloxycarbonylamino sulfones with dialkyl trimethyl silyl phosphites in the presence of FeCl₃ as a catalyst. The products were formed in high yields (86–94%) within 2–4?h. The catalyst is inexpensive, easily available, and highly active. The unreacted dialkyl trimetyl silyl phosphites can easily be removed from the products due to their low boiling points. The sulfones can conveniently be prepared and are generally stable.     

FeCl_3: Highly Efficient Catalyst for Synthesis of α-Amino Nitriles

α‐Amino nitriles are synthesized by the three‐component coupling reaction of aldehydes, amines and trimethylsilyl cyanide using FeCl₃ as a solid acid catalyst, under solvent‐free conditions in good yields. The catalyst was recovered by simple filtration and was recycled in subsequent reactions.     

Reverse Atom Transfer Radical Polymerization of Acrylonitrile Catalyzed by FeCl3/Lactic Acid

Reverse atom transfer radical polymerization (RATRP) of acrylonitrile (AN) was carried out using azobisisobutyronitrile (AIBN) as initiator, ferric trichloride anhydrous (FeCl₃)/lactic acid (LA) as catalyst system; a ratio of FeCl₃/LA was 1:2 gave the best control. RATRP of AN with N,N-dimethylformamide (DMF) as solvent gave the moderate polymerization rate and the narrowest polydispersity index (PDI). When FeCl₃ was replaced by CuBr₂, RATRP of AN showed a longer induction period. When Cu was added to the CuBr₂-based catalyst system, the induction period was reduced. ¹H-NMR spectra of PAN verified the possibility of controlled/living polymerization for future chain extension.     

Rice-husk-supported FeCl3 nano-particles: Introduction of a mild,efficient and reusable catalyst for some of the multi-component reactions

Rice-husk-supported FeCl₃ nano-particles (FeCl₃–RiH) were prepared and used as an environmentally friendly catalyst in the synthesis of β-amino carbonyl compounds, 1,8-dioxo-octahydro xanthenes, and bis-indolyl methanes from simple and readily available precursor molecules.     

FeCl3·6H2O/C: An Efficient and Recyclable Catalyst for the Synthesis of 2,3-Unsaturated O- and S-Glycosides

A novel method for synthesizing 2,3-unsaturated glycosides has been developed using a handy and eco-friendly immobilized catalyst, FeCl₃·6H₂O/C. A series of 2,3-unsaturated O- and S-glycosides were obtained for bioassay from corresponding 3,4,6-tri-O-acetyl-D-glucal and D-galactal in good to excellent yields (56%–99%) and high anomeric selectivity (α/β = 7:1 to >19:1). Furthermore, the catalyst was efficient on gram-scale reactions and recyclable for at least three times.     

Silica-Supported Ferric Chloride (FeCl3-SiO2): An Efficient and Recyclable Heterogeneous Catalyst for the Preparation of Arylaminotetrazoles

An efficient method for preparation of 5-arylamino-1H-tetrazole and 1-aryl-5-amino-1H-tetrazole derivatives is reported using FeCl₃-SiO₂ as an effective heterogeneous catalyst. Generally, when the substituent in arylcyanamide is a strongly electron-withdrawing group, the position of the equilibrium would shift toward 5-arylamino-1H-tetrazole, whereas with an electron-releasing substituent, the position of the equilibrium would shift toward 1-aryl-5-amino-1H-tetrazole.     

Iron salt, a cheap, highly efficient and environment-friendly metal catalyst for Se-Se bond cleavage and the further reaction with methylenecyclopropanes under mild conditions

FeCl₃ was found to be a good catalyst in Se-Se bond cleavage. Further electrophilic additions to methylenecyclopropanes provide a convenient access to diphenylselenylcyclobutanes. Comparing with other Lewis acids, FeCl₃ is much cheaper and the reaction conditions are milde and more tolerance to air and moisture.     

FeCl3 as Lewis acid catalyzed one-pot three-component aza-Friedel-Crafts reactions of indoles, aldehydes, and tertiary aromatic amines

A new strategy for the synthesis of 3-diarylmethyl indoles was developed through FeCl₃ as Lewis acid catalyzed three-component aza-Friedel-Crafts reactions of indoles, aldehydes, and tertiary aromatic amines in one-pot. The reactions generated the corresponding 3-diarylmethyl indoles in good yields under mild reaction conditions by using less expensive, readily available, and environmentally benign iron catalyst. It is important to note that the key feature of this reaction is operational simplicity.     

The effect of initiators and oxidants on the morphology of poly [(±)‐2‐(sec‐butyl) aniline] a chiral bulky substituted polyaniline derivative

The nano and micro sphere synthesis of chiral bulky substituted polyaniline from monomer (±)‐2‐sec‐butylaniline in bulk and template‐free method (rapid mixing) was done successfully using ammonium peroxydisulfate (APS) and FeCl₃·6H₂O as oxidants. The effect of initiators such as p‐phenylendiamine and 1,4‐benzenediamine, temperature and concentration of monomer on morphology is demonstrated by scanning electron microscopy (SEM) images. The nano and micro sphere morphology was obtained using initiators. Smallest particles were achieved when 1,4‐benzenediamine was used as initiator in the presence of FeCl₃·6H₂O as oxidant. By increasing the concentration of monomer more uniform spheres were obtained. Characterization was made via FT‐IR, UV–Vis, ¹H and ¹³C‐NMR spectroscopy. Elemental analysis and electrical conductivity of products are also presented. All analysis data are in good agreement with nigraniline oxidation state of polyaniline. Copyright © 2015 John Wiley & Sons, Ltd.     

Ag/PANI/Fe_2O_3复合纳米粒子的合成与催化性能

借助于PANI的还原性质,PANI/Fe2O3复合载体与AgNO3发生表面氧化还原反应,合成了Ag/PANI/Fe2O3复合纳米粒子。TEM和XRD结果表明,立方晶系纳米银的平均粒径10nm。FTIR结果表明,Ag与PANI及Fe2O3复合载体之间不存在化学键合作用,但由于PANI与Ag之间的电子相互作用,Ag/PANI/Fe2O3复合纳米粒子的FTIR吸收峰发生蓝移。Ag/PANI/Fe2O3复合纳米粒子对于间硝基苯磺酸钠的硼氢化钠还原反应表现出良好的催化活性,30min内间硝基苯磺酸钠的转化率达到86.77%。     

Deoximation Reaction in Room Temperature Ionic Liquids under Mild Conditions

Deoximation in metal chloride ionic liquids based on 1‐alkyl‐3‐methylimidazolium and triethylene ammonium cations, such as AmimBr(Cl)‐MCl_x(A=ethyl, butyl, benzyl; M=Al, Fe, Cu, Sn and Zn; x=2, 3) and Et₃NHCl‐FeCl₃ were investigated under mild conditions. Ferrate chloride ionic liquid was proved to be an effective catalyst for deoximation of cyclohexanone oxime, exhibiting high conversion of oximes and selectivity to cyclohexanone. Good performance for the deoximation of other oximes such as salicylald oxime, acetone oxime, benzophenone oxime, 4‐nitrobenzald oxime, acetophenone oxime, 2‐chlorobenzaldehyde oxime, Acetald oxime, 2‐butanone oxime and (1R)‐camphor oxime was also achieved with bmimBr‐FeCl₃ as catalyst and solvent. The deoximation was determined to carry out via acid‐catalytic hydrolysis and the reaction mechanism was proposed.     

A Convenient Method for the Preparation of 1,5‐Diaryl‐3‐(arylamino)‐1H‐pyrrol‐2(5H)‐ones

A simple and eco‐friendly method for the preparation of 1,5‐diaryl‐3‐(arylamino)‐1H‐pyrrol‐2(5H)‐ones via the cyclo‐condensation reaction of aldehydes, amines and ethyl pyruvate in the presence of silica supported ferric chloride (SiO₂‐FeCl₃) as reusable heterogeneous catalyst is described. The present methodology offers several advantages such as excellent yields, simple procedure and short reaction times.     

FeCl3-SiO2 as a reusable heterogeneous catalyst for the synthesis of 5-substituted 1H-tetrazoles via [2+3] cycloaddition of nitriles and sodium azide

An efficient method for the preparation of 5-substituted 1H-tetrazole derivatives is reported using FeCl₃-SiO₂ as an effective heterogeneous catalyst. This method has the advantages of high yields, simple methodology, and easy work-up. The catalyst can be recovered by simple filtration and reused delivering good yields.     

Influence of the texture of chromia catalysts on their activity in synthesis of 2-methylthiophene

The texture of Cr₂O₃-K₂O/Al₂O₃catalysts containing oxides of rare earth elements (REE) was studied. The catalysts are used for the synthesis of 2-methylthiophene by the reaction of H₂S with n-pentane or piperilene. The heterocyclization of n-pentane is a consecutive reaction involving a step of dehydrogenation of initial hydrocarbon. At this step the texture of the catalyst affects the yield of 2-methylthiophene. The yield of 2-methylthiophene obtained from piperilene and I₂S is independent of the catalyst texture.     

Practical neutral aromatic nitration with nitrogen dioxide in the presence of heterogeneous catalysts under moderate oxygen pressure

A practical neutral aromatic nitration process using nitrogen dioxide in the presence of FeCl₃ · 6H₂O under 40–100 psig of oxygen was developed, and nitration of several aromatic compounds, including the deactivated nitrobenzene, was performed in a successful manner. The correlation of reaction rate with equivalents nitrogen dioxide, oxygen pressure, amount of catalyst and temperature was investigated through the nitration of benzene. Following the optimization of reaction conditions, the nitration of benzene was scaled up to 476 mol. Furthermore, inorganic solid catalysts with pore size over 5 Å and surface area over 100 m²/g were applied to newly developed neutral nitration.     

硅酸盐对Ferrihydrite相转化为α-Fe2O3微粒形貌的调控作用

以Ferrihydrite(又称水合氧化铁hydrous iron oxide)为反应前驱物, Fe(II)为催化剂, 在微量Na₂SiO₃存在下, 控制pH＝6～9范围内合成出了亚微米级纺锤形和准立方形α-Fe₂O₃微粒. 研究了初始pH, Na₂SiO₃浓度, Ferrihydrite老化方式对相转化时间和产物形貌的影响, 利用XRD, SEM等手段对产物进行了表征. 结果表明, Na₂SiO₃对Ferriihydrite催化相转化有一定的抑制作用, 是影响其相转化过程及产物形貌的关键. 在弱碱性条件下, [Si]/[Fe^3＋]为0.01时可直接获得纺锤形(轴比≥2)或准立方形(300～400 nm) α-Fe₂O₃粒子, 并对形成机理进行了初步讨论.     

Synthesis and ferromagnetic properties of composites of a water-soluble polyaniline copolymer containing iron oxide

Composites of water-soluble conducting polyaniline copolymers, poly(aniline-co-aminobenzenesulfonic acid) (PAOABSA), containing γ-Fe₂O₃magnetic particles with nanometer size, were synthesized by a chemical method. The ferromagnetic properties of the resulting PAOABSA composites were measured as a function of the pH value of the reaction solution, the sulfonated degree of the copolymer, and the concentration of FeCl₂. The structure of the composites was characterized by means of elemental analysis, FTIR, XPS, and X-ray diffraction. It was found that increasing the pH value of the reaction solution and the concentration of FeCl₂ is favorable for an enhancement of the saturated magnetization. As high as 33.2 emu/g of saturated magnetization for the PAOABSA composites was observed. No hysteresis loop (i.e. H_c = 0) was observed, which is independent of the preparation conditions. Structure characterizations show that iron oxide existing in the composite is mainly γ- Fe₂O₃, which is responsible for the ferromagnetic properties of the PAOABSA composites, whereas γ- Fe₂O₃ magnetic particles nanometer in size (∼85 nm) may be attributed to a lower coercive force (i.e. H_c = 0) of the composites. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2749–2755, 1998