选择性氧化的研究: 盐酸三甲胺三氧化铬的制备及应用

铬(Ⅵ)类氧化剂在选择性氧化中有着特殊的应用。六十年代末,随着 Collins 研制的氧化剂的出现,人们开始热衷于寻找新的氧化剂。以后研制出的一批铬(Ⅵ)氧化剂,基本上解决了把伯醇和仲醇转变为相应的羰基化合物的难题。但是,到目前为止,关于选择性更高的氧化剂的报道还很少。     

Quinaldinium Chlorochromate Supported on Alumina: A New and Efficient Reagent for the Oxidation of Alcohols

Summary. The new, mild chromium(VI) oxidizing agent, quinaldinium chlorochromate supported on neutral alumina, was prepared as a stable yellow solid. The reagent is suitable to oxidize various primary and secondary alcohols to the corresponding carbonyl compounds and anthracene to anthraquinone in good yields.     

溴代二甲氨基苯基荧光酮的合成及其与铁显色反应的研究

报道了溴代二甲氨基苯基荧光酮（简称BDMAF）的合成及鉴定；研究了在第二配体及表面活性剂存在下，BDMAF与微量铁的显色反应，在乙酰丙酮及CTMAB存在下，铁与显色剂形成蓝色配合物，其表观摩尔吸光系数达1.61×10^5L/mol·cm。以EGTA作为掩蔽剂可不经分离直接测定某些纯金属及合金中的微量铁。     

Aromatization of Hantzsch 1,4‐Dihydropyridines in Solventless System Using Glycinium Chlorochromate

Glycinium chlorochromate (GCC) supported onto silica gel was used as an effective oxidizing agent for the aromatization of 1,4‐dihydropyridines to corresponding pyridine.     

Using of Taguchi Method for Experimental Design of Crystallization Processes of an Oxidant: Tetraethylammonium Chlorochromate (VI)

Abstract  Crystallization of tetraethylammonium chlorochromate (C₂H₅)₄N[CrO₃Cl], TEACC, with desirable particle size as a performance characteristic was used to illustrate the design procedure. Taguchi design of experiments (DOE) method has been used for to plan a minimum number of experiments and optimization of crystallization processes. Four factors, which influence the crystal size, crystal growth and nucleation, were chosen. These factors are concentration, temperature, type of solvent and method of crystallization. After optimization the results show that concentration is most effective factor that has largest percent of contribution 53.26% and type of solvent is least effective factor that has smallest percent of contribution 4.33%. The optimum conditions are vapor diffusion as method, 0.043 g/15 mL for concentration, 0 °C for temperature and acetonitrile as solvent. These conditions must be produced suitable crystals for single crystal X-ray diffraction experiment. These results confirmed by experimental data and the crystals of the optimum conditions found to have suitable properties for single crystal X-ray diffraction. These crystals had sent for single crystal X-ray diffraction and diffraction data gathered successfully. A red block crystal was mounted on a glass fiber. The X-ray data determined monoclinic system, space group C2(#5), with a = 12.023(3), b = 7.998(2), c = 14.527(4) ?, β = 114.187(4)°, V = 1274.4(6) ?³ and Z = 4. Index Abstract  The Taguchi design of experiments (DOE) method has been used for to plan a minimum number of experiments and optimization of crystallization processes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Ammonium Chlorochromate Adsorbed on Montmorillonite K-10: Oxidative Deprotection of Tetrahydropyranyl Ethers Using Microwaves in a Solventless System

Summary.  Tetrahydropyranyl ethers were rapidly and selectively oxidized to the corresponding carbonyl compounds by clay supported ammonium chlorochromate under solvent free conditions using microwaves. Received July 25, 2000. Accepted September 7, 2000     

盐酸甲胺三氧化铬的制备及其对α,β-不饱和醇的选择性氧化

有机化合物的选择性氧化,在有机合成上是一个很重要而又复杂的问题。由于化学家致力于这方面的研究,现已发现许多选择性氧化剂,基本上解决了把伯醇和仲醇氧化成相应的羰基化合物的难题。但是,选择性更高的氧化剂的报道还比较少。     

Synthesis,characterization, X-ray structural analysis and study of oxidative properties of tetraethylammonium chlorochromate

Tetraethylammonium chlorochromate(VI), Et₄N[CrO₃Cl] is easily synthesized in nearly quantitative yield using a direct reaction of chromium(VI) oxide and tetraethylammonium chloride and characterized by elemental analysis, IR, UV/Visible, ¹H-NMR and ¹³C-NMR techniques and single-crystal X-ray diffraction analysis (monoclinic system, space group C2(#5), with a = 12.023(3), b = 7.998(2), c = 14.527(4) Å, β = 114.187(4)°, V = 1274.4(6) ų and Z = 4). X-ray data determined the CH ··· O hydrogen bond that forms between the ethyl hydrogen of the cation and oxygen of the anion. This compound is a versatile reagent for efficient and selective oxidation of organic substrates, in particular for alcohols to their corresponding aldehydes or ketones, under mild conditions.