Synthesis of quaternary succinimides promoted by Ferric Nitrate

An efficient protocol has been accomplished for the synthesis of quaternary α-aminosuccinimides in toluene medium involving 2-phenylimidazo[1, 2-a]pyridine in a one-pot reaction promoted by Ferric Nitrate at 120?°C. The protocol presented herein, is for the first time, via a novel transformation where Ferric Nitrate promotes imidazo[1,2-a]pyridine structural metamorphosis to the title compound quaternary succinimides. High compatibility, easy work-up, and excellent yields are the advantages of this protocol. The quaternary α-aminosuccinimides are expected to have great potential in synthesizing quaternary α-amino acids and applications in medicinal chemistry.     

Ferric Chloride Catalyzed Isomerization and Cyclization of Geraniol, Linalool and Nerol

Geranyl pyrophosphate, linalyl pyrophosphate and neryl pyrophosphate are known to be important precursors for biosynthesis of cyclic terpenoids, and a variety of cationic intermediates have been suggested to be involved in their skeletal rearrangements1. Ferric chloride has recently been used as a Lewis acid to catalyze Friedel-Crafts reactions2, synthesis of esters and acetals3, a-glycosidation of peracetylated sugars4 and cyclization of 2-(trimethylsilylmethyl) pentadienal5. Therefore, i…     

Facile Synthesis of Bis(indolyl)methanes catalyzed by Ferric Dodecyl Sulfonate [Fe(DS)3] in Water at Room Temperature

Ferric dodecyl sulfonate [Fe(DS)₃] is easily prepared and can be used as a Lewis acid surfactant catalyst in water to conduct the highly efficient electrophilic substitution reaction of indoles with aliphatic or aromatic aldehydes at room temperature.     

Volumetric determination of small amounts of uranium : Chromous chloride as reducing agent

A volumetric method is proposed for the rapid determination of small amounts of uranium. The hexavalent uranium is reduced to the quadrivalent state by chromous chloride, the excess of which is destroyed by air oxidation. A low potential redox indicator is used to follow the reduction and air oxidation. Ferric sulphate is added to the solution and the resulting ferrous ion titrated with dichromate solution.     

FeCl3催化羰基化合物的还原卤代反应

在甲基二氯硅烷作用下, FeCl₃能催化羰基化合物(醛、酮)的还原氯代反应, 得到相应的氯代产物; 在甲基二氯硅烷、PBr₃或NaI作用下, FeCl₃可以催化羰基化合物(醛、酮)的还原溴代或碘代反应, 分别以良好的收率得到相应的溴代烷或碘代烷.     

Reduction of Carbonyl Compounds to Alcohols Using Ferric Chloride - Zinc-Dimethylformamide-Water System

Carbonyl Compounds have been reduced into the corresponding alcohols in moderate to good yields at room temperature using Ferric Chloride-Zinc-Dimethyl-Formamide-Water System.     

Isolation and spectral characteristics of Ferric Iodide

Ferric iodide is isolated pure for the first time as a dark purple solid when a hexane solution of diiodotetracarbonyliron(II) and diiodine is exposed to actinic radiation. Its identity is confirmed by elemental analysis and quantitative conversion to the known tetraiodoferrate(III) by treatment with tetra-n-butylammonium iodide. Although persistent in the solid state, ferric iodide is readily decomposed in solution to ferrous iodide and 0.5 mol diiodine quantitatively.     

含铁镍皂石的合成与交联的研究

用水热法合成出铁皂石和铁镍皂石,用羟基铝作交联剂制备了交联粘土.经XRD、DTA、IR、TPR、Mssbauer谱和化学分析表征,证明铁进入了粘土层骨架,铝交联可能作用在四面体铁上.形成Al_p-O-Fe键.     

十二烷基磺酸铁催化合成丙酸正丁酯

以十二烷基磺酸铁催化合成了丙酸正丁酯。实验结果表明最佳反应条件为：丙酸100mmol,n(丙酸)：n(正丁醇)=1．0：1．2,十二烷基磺酸铁0．8g(约1．0mmol),带水剂环己烷6mL,回流分水60min,酯化率94．6％。催化剂重复使用5次仍保持较高活性。     

Nicotinium Dichromate (=3‐Carboxypyridinium Dichromate; NDC) as an Efficient Reagent for the Oxidative Deamination of Amines and Aminophosphonates

A new method for the efficient synthesis of aldehydes, ketones, and oxophosphonates from various types of amines (primary and secondary) and aminophosphonates via oxidative deamination by nicotinium dichromate (=3‐carboxypyridinium dichromate; NDC) is described.     

Triphenylmethylphosphonium Dichromate: An Effective and Chemoselective Reagent for Oxidation of Benzylic Alcohols to the Corresponding Aldehydes and Ketones

An efficient and straightforward method for oxidation of the benzylic alcohols to the corresponding aldehydes and ketones has been accomplished using triphenylmethylphosphonium dichromate (MTPPD) under solvent-free conditions with high chemoselectivity. The reaction is fast with good yields and straightforward workup.     

Aromatization of Various 1,4‐Dihydropyridines by Tetrabutylphosphonium Dichromate (TBPDC) under Conventional Heating and Microwave Irradiation

Tetrabutylphosphonium dichromate (TBPDC) has been found an efficient oxidizing agent for the aromatization of various 1,4‐dihydropyridines to their pyridine derivatives in refluxing acetonitrile and also under microwave irradiation. Short reaction times and clean workup are the advantages of this method.     

Construction,assessment and applications of a dichromate-selective liquid membrane electrode based on tetrapentylammonium dichromate

A dichromate-selective liquid-membrane electrode based on tetrapentylammonium dichromate dissolved in 2-nitrotoluene is described. The electrode exhibits rapid and linear response to the activity of Cr(VI) anions in the range 5 × 10^?4–2 × 10.2 M dichromate; the slopes of the calibration graphs depend on the acidity. The electrode is useful for end-point indication in titrations of iron(II), arsenic(III), ascorbic acid, thiobarbituric acid, thiourea, and cysteine with dichromate. The electrode is also used as indicator electrode in a potentiometric reaction-rate method for the determination of hydroxyl-containing organic compounds, based on their oxidation by dichromate in acidic solution; ethanol, isopropanol, ethylene glycol, propylene glycol, butylene glycol, and several carbohydrates were determined with a mean error of 1%. The method is applied to determine the ethanol content of alcoholic beverages. Kinetic data are given for the dichromate/ethanol reaction.     

3-Carboxypyridinium Dichromate (NDC) and (4-Carboxypyridinium Dichromate (INDC). Two New Mild,Stable, Efficient,and Inexpensive Chromium (VI) Oxidation Reagents

Two mild new chromium (VI) reagents derived from nicotinic acid and isonicotinic acid are described. Nicotinium dichromate (NDC) and isonicotinium dichromate (INDC) oxidize alcohols into carbonyl compounds, mercaptans into disulfides and hydroquinones into quinones. Oxidtion of polynuclear aromatic hydrocarbons is made. Pyridine assisted oxidations by means of these reagents are also described.     

1-Butyl-4-aza-1-azoniabicyclo[2.2.2]octane Dichromate (BAAOD): An Efficient and Novel Reagent for Oxidation of Sulfides to the Corresponding Sulfoxides

This article describes an efficient and easy method for oxidation of sulfides 1 to their corresponding sulfoxides 2 with 1-butyl-4-aza-1-azoniabicyclo[2.2.2]octane dichromate (BAAOD) under nonaqueous conditions in high yields.     

New oxidative demetalation protocol for molybdenum pi-complexes: enantiocontrolled synthesis of unsaturated ketones and lactones

An efficient and general oxidative demetalation of (eta(3)-allyl)molybdenum complexes using pyridinium dichromate allows the introduction of a carbonyl group at an allylic terminus of the pi-system. The process takes place with high regiocontrol and can lead to the preparation of unsaturated ketones and lactones of high enantiopurity.     

Chemoselective Oxidation of Benzylic Alcohols and Hydroquinones with bis-(2,4,6-Trimethylpyridinium) Dichromate (BTMPDC) as an Efficient and New Oxidizing Agent

A simple, efficient, and chemoselective oxidation of benzylic alcohols to the corresponding aldehydes and ketones and also hydroquinones to the benzoquinones using bis-(2,4,6-trimethylpyridinium) dichromate (BTMPDC) in acetonitrile is described. A good range of primary and secondary benzylic alcohols and a limited range of hydroquinones were selectively oxidized under reflux conditions in reasonable yields.     

Oxidation of Benzyl Alcohols under Mild Heterogeneous Conditions

A combination of iodic acid with ammonium dichromate in the presence of wet SiO₂ was used as an efficient oxidizing agent for the transformation of benzyl alcohols to the corresponding aldehydes and ketones in n-hexane or without a solvent at room temperature with excellent yields.     

IMMEDIATE AND HIGH YIELDING SOLVENT-FREE OXIDATION OF SILYL AND PYRANYL ETHERS TO THEIR CORRESPOUNDING CARBONYL COMPOUNDS WITH ZINC DICHROMATE TRIHYDRATE (ZnCr2O7·3H2O)

Zinc dichromate trihydrate (ZnCr₂O₇·3H₂O) is an efficient reagent for the immediate deprotection of aromatic and aliphatic silyl and pyranyl ethers into their corresponding carbonyl compounds in high yields at room temperature under solvent-free conditions.     

Chromium(VI) Forms Thiolate Complexes with gamma-Glutamylcysteine, N-Acetylcysteine, Cysteine, and the Methyl Ester of N-Acetylcysteine

Reaction of potassium dichromate with gamma-glutamylcysteine, N-acetylcysteine, and cysteine in aqueous solution resulted in the formation of 1:1 complexes of Cr(VI) with the cysteinyl thiolate ligand. The brownish red Cr(VI)-amino acid/peptide complexes exhibited differential stability in aqueous solutions at 4 degrees C and ionic strength = 1.5 M, decreasing in stability in the order: gamma-glutamylcysteine > N-acetylcysteine > cysteine. (1)H, (13)C, and (17)O NMR studies showed that the amino acids act as monodentate ligands and bind to Cr(VI) through the cysteinyl thiolate group, forming RS-Cr(VI)O(3)(-) complexes. No evidence was obtained for involvement of any other possible ligating groups, e.g., amine or carboxylate, of the amino acid/peptide in binding to Cr(VI). EPR studies showed that chromium(V) species at g = 1.973-4 were formed upon reaction of potassium dichromate with gamma-glutamylcysteine and N-acetylcysteine. Reaction of potassium dichromate or sodium dichromate with N-acetylcysteine and the methyl ester of N-acetylcysteine in N,N-dimethylformamide (DMF) also led to the formation of RS-Cr(VI)O(3)(-) complexes as determined by UV/vis, IR, and (1)H NMR spectroscopy. Thus, an early step in the reaction of Cr(VI) with cysteine and cysteine derviatives in aqueous and DMF solutions involves the formation of RS-CrO(3)(-) complexes. The Cr(VI)-thiolate complexes are more stable in DMF than in aqueous solution, and their stability towards reduction in aqueous solution follows the order cysteine < N-acetylcysteine < gamma-glutamylcysteine < glutathione.