Silica Sulfuric Acid/Sodium Dichromate Dihydrate as an Efficient Heterogeneous Method for the Oxidation of Alcohols Under Mild Conditions

A combination of silica sulfuric acid and sodium dichromate dihydrate in the presence of wet SiO 2 were used as an effective oxidizing agent for the oxidation of alcohols to their corresponding aldehyde or ketone derivatives in dichloromethane or toluene with excellent yields.     

Silica Sulfuric Acid and Al(HSO4)3: As Efficient Catalysts for the Formylation of Alcohols by Using Ethyl Formate under Heterogeneous Conditions

A mixture of ethyl formate and a catalytic amount of silica sulfuric acid or Al(HSO₄)₃ as suitable formylating systems can formylate various alcohols to their corresponding formate ester derivatives under mild, nearly neutral and heterogeneous conditions at room temperature with good to excellent yields.     

Cerium Polyoxometalate as a Reusable Catalyst for Acetylation and Formylation of Alcohols

Summary. Efficient esterification of primary and sterically-hindered secondary or tertiary alcohols with acetic anhydride was achieved in the presence of ammonium decatungestocerate(IV) icosahydrate, (NH₄)₈[CeW₁₀O₃₆]·20H₂O, as catalyst in high yields. Primary and secondary alcohols were also converted to their corresponding acetates and formates with acetic acid and ethyl formate in the presence of this catalyst. Easy work-up, non-toxicity, reusability, and stability of the catalyst are noteworthy advantages of this method.     

Efficient Oxidation of Alcohols with KBrO 3 in the Presence of Silica Chloride and Wet SiO 2

Alcohols were oxidized to their corresponding carbonyl compounds with KBrO 3 in the presence of silica chloride and wet SiO 2 , in solution and under solvent free conditions.     

Potassium Fluoride Assisted Selective Acetylation of Alcohols with Acetic Acid

Abstract

Potassium fluoride promotes the acetylation of primary and secondary alcohols with acetic acid in excellent yield. Phenols are not affected under this reaction conditions. The groups like double bond, chloro, methoxy, benzyloxy, thiol, and nitro remain unaffected.     

Acetylation of Alcohols Catalyzed by Dodeca-tungsto(molybdo)phosphoric acid

Summary. Acetylation of primary, secondary, and tertiary alcohols was carried out in some refluxing alkyl acetates and in two carboxylic acids with the participation of catalytic amounts of H₃PW₁₂O₄₀, H₃PMo₁₂O₄₀, and H₁₄P₅W₃₀O₁₁₀ with good yields and high stereo(regio)specificity under mild reaction condition. H₃PW₁₂O₄₀ and H₃PMo₁₂O₄₀ have also shown excellent reactivity in the formylation of 1-butanol with ethyl formate at room temperature and in short reaction times. Heteropolyacid catalysts could be separated after a simple work up and reused for several times.     

Efficient Method for Iodination of Alcohols using KI/Silica Sulfuric Acid (SSA)

A straightforward and effective procedure for the conversion of benzylic and allylic alcohols to the corresponding iodides using KI/SSA in acetonitrile at room temperature.     

Silica Chloride as a Mild and Efficient Reagent for Acetylation of Alcohols

A variety of alcohols underwent acetylation with acetic anhydride in the presence of silica chloride. All reactions were performed at room temperature and under completely heterogeneous conditions in good to high yields.

     

Rapid and Efficient Method for Acetylation of Alcohols and Phenols with Acetic Anhydride Catalyzed by Silica Sulfate

A rapid and efficient method is described for acetylation of a series of alcohols and phenols with acetic anhydride catalyzed by silica sulfate solid acid at room temperature or at refluxing temperature in excellent yield.     

Solvent‐free Oxidation of Alcohols by Silica Sulfuric Acid/Sodium Dichromate Dihydrate or Potassium Permanganate/Wet SiO2 System

A combination of silica sulfuric acid and sodium dichromate dihydrate or potassium permanganate in the presence of wet SiO₂ was used as an effective oxidizing agent for oxidation of alcohols to their corresponding aldehydes or ketones in solvent free conditions.     

Silica Sulfuric Acid as an Inexpensive and Recyclable Solid Acid Catalyzed Efficient Synthesis of Quinolines

Summary. Silica sulfuric acid as an inexpensive and recyclable solid acid efficiently catalyzes the Fridedl?nder synthesis of quinolines through a condensation reaction of a 2-aminoaryl ketone with an activated α-CH acid compound under solvent-free conditions in high yields at 100°C.     

Al(HSO4)3 as an Efficient Catalyst for the Acetylation of Alcohols in Solution and Under Solvent Free Conditions

Summary. Alcohols are acetylated in a mild, clean, and efficient reaction with acetic anhydride in the presence of a catalytic amount of Al(HSO₄)₃ in solution and under solvent free conditions. All reactions were performed at room temperature in good to high yields.     

柠檬烯和柠檬烯氧化物与硫酸的非均相反应动力学

主要对天然挥发性有机物柠檬烯和柠檬烯氧化物在30%-80% (w)硫酸表面的非均相吸收反应进行了研究, 借以评估天然挥发性有机物与大气环境中的酸性气溶胶的反应活性. 采用自行搭建的配以单光子激光电离飞行时间质谱的湿壁流动反应管的设备对柠檬烯及其氧化物在硫酸表面的非均相吸收动力学进行了测定,计算了稳态摄取系数(γ). 实验结果表明, 柠檬烯氧化物在硫酸表面比只含有双键的柠檬烯的反应活性高, 室温下柠檬烯氧化物在30%-50% (w)硫酸上对应的稳态摄取系数是(7.100±0.023)×10^-5-(8.150±0.162)×10^-3. 此外, 还利用气相色谱-质谱(GC-MS)联用和电喷雾电离质谱(ESI-MS)对柠檬烯氧化物与硫酸的体相反应产物进行了研究, 产物包括单萜烯、松油醇、水合萜二醇和水合萜二醇二硫酸酯. 其中, 水合萜二醇二硫酸酯作为有机硫酸酯的一种, 能够改变气溶胶的吸湿性, 增强云凝结核的活性, 对于大气中灰霾的形成可能有明显的促进作用.     

Chromium Trioxide Supported onto Wet Silica Gel: Rapid Oxidation of Alcohols to Carbonyl Compounds Under Microwave Irradiation in Solventless System

In an environmentally benign system, alcohols are rapidly oxidized to carbonyl compounds using CrO 3 supported onto wet silica gel as an oxidant under microwave irradiation.     

Recovery of Phosphate from Steel Manufacture Slag by Sulfuric Acid Treatment

The sulfuric acid treatment on steel manufacture slag (SMS) was performed to recover P resource. P element in SMS was successfully removed. Final products were a solid of CaSO 4 /SiO 2 and a solution containing PO 4 3 m , Fe, Al, Mg, and Mn.     

Efficient Acetylation of Alcohols,Phenols, and Amines Catalyzed by Melamine Trisulfonic Acid (MTSA)

Melamine trisulfonic acid (MTSA) was easily prepared by the reaction of melamine with neat chlorosulfonic acid at room temperature. This reagent can be used as an efficient catalyst for the acetylation of alcohols, phenols, and amines with Ac₂O under mild and completely heterogeneous reaction conditions.     

A Mild and Efficient Method for Chemoselective Silylation of Alcohols Using Hexamethyldisilazane in the Presence of Silica Chloride

Reaction of alcohols with hexamethyldisilazane in the presence of silica chloride provides efficiently the corresponding trimethylsilyl ethers. This system discriminates absolutely amines and thiols from alcohols.     

Selective Acetylation of Alcohols and Amines with Ethyl Acetate in the Presence of H<Subscript>6</Subscript>[PMo<Subscript>9</Subscript>V<Subscript>3</Subscript>O<Subscript>40</Subscript>] as the Catalyst

Summary. Acetylation of various alcohols and benzyl amine was tested in the presence of H₆[PMo₉V₃O₄₀], a mixed addenda heteropolyacid, in ethyl acetate under reflux condition. Phenols and anilines are not affected under the reaction conditions. Selective transestrification of alcohols can be achieved in the presence of phenol and aniline derivatives using this method.     

Silica Sulfuric Acid as an Efficient Reagent for the Synthesis of Symmetrical Ethers Under Mild and Heterogeneous Conditions

A mild and efficient method for the synthesis of symmetrical ethers using silica sulfuric acid is reported. All reactions are performed under compeletly heterogeneous conditions in good to high yields.     

Silica Sulfuric Acid Catalysis the Oxidation of Organic Compounds with Sodium Bromate

Abstract

The oxidation of organic compounds by sodium bromate/silica sulfuric acid under solvent‐free conditions and in CH₂Cl₂ have been studied at room temperature.