盐酸三甲胺三氧化铬／硅胶载体试剂的制备及其对苯偶姻体系的氧化

报道了盐酸三甲胺三氧化锆／硅胶载体试剂的制备方法及其对苯偶姻的氧化反应。该试剂制备简单，用于地苯偶姻的氧化，高收率地得到相应的苯偶酰在化合物，并且反应条件温和，产物易分离。     

α,β-不饱和醇的选择性氧化反应研究——两种新型聚合物载体氧化剂的合成及选择性

近年来,应用聚合物载体氧化剂进行醇类氧化反应的研究已有报道,蔡坤等人采用盐酸三甲胺为配体的三氧化铬,制成对醇类具有高度氧化选择性的氧化剂。我们将三甲胺基和四甲胺基用反应选择性较好的低交联凝胶树脂固载化,合成了未见报道的重铬酸型叔胺树脂氧化剂(Ⅰ)和不同于Cainelli氧化剂的低交联凝胶重铬酸型季铵树脂氧化剂(Ⅱ)。合成路线如下:     

盐酸三甲胺三氧化铬对二醇及肟的选择性氧化

前文曾报道盐酸三甲胺三氧化铬(TCC)的制备方法及对一些一元醇的氧化实验,结果发现TCC对一元醇的氧化有很好的选择性。本文在此基础上,用TCC在DMF中作了一些对二醇及肟的氧化实验,实验表明:TCC在DMF中只氧化二醇中的苄基型羟基而不氧化     

三氧化铬二吡啶、三氧化铬吡啶盐酸盐——两种有效的专用氧化剂

近年来,文献[1]陆续报道了多种能选择地将伯、仲醇氧化为醛和酮的专一氧化剂,例如四醋酸铅吡啶,铬酸叔丁酯,Ｎ氯代丁二烯亚胺,二甲硫醚,硝酸氨铈,三氧化铬的吡啶溶液,其中有些氧化剂制备较复杂,或是制备成本较高,使之应用范围较窄。而三氧化铬的吡啶溶液由于氧化醇时条件温和,产物分离方便,在近年来得到了广泛的应用,例在合成前列腺素和甾体的醛的中间体时,得到了几乎定量的产物。我们对三氧化铬吡啶溶液中最具代表性的氧化剂三氧化铬二吡啶及三氧化铬吡啶盐酸盐的合成、应用及氧化机理作了一些探讨。1　实验部分11　试剂和仪器文中所用试剂…     

氯化铵三氧化铬在干反应中对苄醚的选择性氧化

本文报道氯化铵三氧化铬(ACC)是具有高选择性的氧化剂, 在无溶剂的干反应中, 可以把苄醚氧化成相应的苯甲酸酯, 且顶点满意的产率.     

用锰(Ⅱ)-氨三乙酸-溴代十六烷基三甲胺-高碘酸钾-灿烂甲酚蓝体系催化光度法测定锰

基于存在活化剂氨三乙酸和增敏剂溴代十六烷基三甲胺，锰（Ⅱ）催化高碘酸钾氧化灿烂甲酚蓝的反应，拟定了测定痕量锰的催化光度法，讨论了有关反应机理。本法由于添加了溴代十六烷基三甲胺，灵敏度揭高2．5倍，测定锰含量线性范围为8．0×10－4～8．0×10－3mg／L，检出限为7．0×10－5mg／L，相对标准偏差为4．7％（n＝11），可用于测定茶叶和水样中的锰。     

用锰（IUI）—氨三乙酸—溴代十六烷基三甲胺—高碘酸钾—烂灿甲酚蓝…

基于存在活化剂氨三乙酸和增敏剂溴代十六烷基三甲胺，锰（Ⅱ）催化高碘酸钾氧化灿烂甲酚蓝的反应，拟定了测定痕量锰的催化光度法，讨论了有关反应机理。本法由于添加了溴代十六烷基三甲胺，灵敏度提高２．５倍，测定锰含量线性范围为８．０×１０＾－４￣８．０×１０＾－３ｍｇ／Ｌ，检出限为７．０×１０＾－５ｍｇ／Ｌ，相对标准偏差为４．７％（ｎ＝１１），可用于测定茶叶和水样中的锰。     

Cr－Ag／γ－Al_2O_3催化剂在CO氧化反应中Ag的助催化作用

Ｃｒ－Ａｇ／γ－Ａｌ_２Ｏ_３催化剂在ＣＯ氧化反应中Ａｇ的助催化作用陈平，朱波，钟依均，罗孟飞，李少华，吴红丽（杭州大学催化研究所杭州３１００２８）（杭州大学中心实验室杭州）关键词氧化铬，氧化银，氧化铝，负载催化剂，还原特性，一氧化碳，氧化活性催化燃烧...     

硅胶负载钒磷氧化物催化2,6-二氯甲苯氨氧化反应

对硅胶负载钒磷氧化物（ＶＰＯ）催化剂（ｎ（Ｖ）／ｎ（Ｐ）＝１）催化２,６－二氯甲苯（ＤＣＴ）氯氧化反应进行了研究。考察了反应温度、空气／ＤＣＴ比和氨／ＤＣＴ比等因素对反应的影响。反应温度对氨氧化反应影响较大,空气／ＤＣＴ比和氨／ＤＣＴ比对反应的影响很大。最佳反应条件为：Ｔ＝６７３Ｋ,ｎ（ａｉｒ）／ｎ（ＤＣＴ）＝３０,ｎ（ＮＨ３）／ｎ（ＤＣＴ）＝６．在此条件下,ＤＣＴ转化率为９０％,产率为５７％。与     

四氮二十二烷基杂环色谱固定相及其制备方法和用途

正公布号:CN105664889A公布日:2016.06.15申请人:郑州大学摘要:本发明公开了一种四氮二十二烷基杂环色谱固定相。首先将色谱用多孔球形硅胶用盐酸酸化处理,水洗至中性,实现硅胶表面活化,然后利用闭环反应将丙烯醛与己二胺反应生成的二十二烷基杂环配体与γ-异氰酸丙基三乙氧基硅烷反应,将合成的硅烷杂环修饰到硅胶载体表面,实现固定     

氯铬酸甲铵/硅胶载体氧化剂的制备及其对醇的氧化研究

利用硅胶作载体，负载氯铬酸甲铵盐制备了一种新的载体铬(Ⅵ)氧化剂。该试剂制备方法简单、性质稳定。可在多种反应介质中对伯醇和仲醇氧化，高收率得到相应的醛和酮，反应操作简单，提纯方便。     

Oxidation of alcohols by electrochemically regenerated nickel oxide hydroxide. Selective oxidation of hydroxysteroids

Primary alcohols, α,ω-diols and secondary alcohols are easily transformed into carboxylic acids, dicarboxylic acids or ketones, respectively, by heterogeneous oxidation with nickel oxide hydroxide electrochemically regenerated at a nickel hydroxyde electrode. The results are discussed in comparison to those of the nickel peroxide and chromic acid oxidation. The oxidation rate decreases with increasing steric hindrance of the alcohol, thus allowing the selective oxidation of the 3-position in hydroxysteroids.     

Oxone/Sodium Chloride: A Simple and Efficient Catalytic System for the Oxidation of Alcohols to Symmetric Esters and Ketones

An efficient method for the oxidation of alcohols is presented. The use of catalytic amounts of sodium chloride in combination with oxone allows the conversion primary aliphatic alcohols to symmetric esters. Secondary alcohols can be easily oxidized to ketones, and benzylic alcohols are converted to the corresponding aldehydes. The method is cost effective and enviromentally benign.     

Efficient selective oxidation of alcohols to aldehydes catalyzed by a morpholinone nitroxide

Efficient chemoselective oxidation of primary alcohols to the corresponding aldehydes is described. The transformation is promoted by a catalytic morpholinone nitroxide radical catalyst which can be easily synthesized. A broad range of substrates including aromatic and aliphatic primary alcohols are converted with excellent yields under mild conditions. The control experiments reveal that the morpholinone nitroxide can be used as a selective oxidant for primary alcohols in the presence of secondary alcohols.     

CuCl catalyzed selective oxidation of primary alcohols to carboxylic acids with tert-butyl hydroperoxide at room temperature

Direct oxidation of primary alcohols to the corresponding carboxylic acids is performed highly efficiently at room temperature with anhydrous tert-butyl hydroperoxide in the presence of a catalytic amount of easily available CuCl under ligand free conditions in acetonitrile. Benzylic alcohols are more reactive than aliphatic alcohols, and these benzylic alcohols are selectively oxidized to the corresponding acids in the presence of aliphatic alcohols such as 1-octanol and 1-decanol.     

Heterogeneous oxidation of alcohols with hydrogen peroxide catalyzed by polyoxometalate metal–organic framework

HSiW-MOF, PMo-MOF, HPMo-MOF and PW-MOF were synthesized and characterized by elemental analysis, UV–Vis, FT-IR, cyclic voltammetry and XRD. These compounds were used as catalyst for the selective oxidation of alcohols by hydrogen peroxide. Within them, PW-MOF showed a higher catalytic activity compared to other catalysts in a similar reaction condition. Therefore, PW-MOF catalyst system was successfully used for the selective oxidation of the benzylic, linear and secondary alcohols to the corresponding aldehydes and ketones. Also, allylic alcohols were converted to the corresponding aldehydes with high conversion and significant selectivity. Moreover, PW-MOF was stable to leaching, behaved as true heterogeneous catalysts, easily recovered by filtration, and reused four times with the preserve of the catalytic performance.     

Oxidation of alcohols by TBHP in the presence of sub-stoichiometric amounts of MnO2

Commercially available activated MnO₂ has been investigated as a catalyst for the oxidation of alcohols (phenylethanol, 4-methyl- and 4-methoxybenzyl alcohol, trans-cinnamyl alcohol, cyclohexanol, menthol, perillyl alcohol and myrtenol) by TBHP/decane or TBHP/water in MeCN. The activity is highest for benzylic and allylic alcohols. Secondary alcohols yield ketones with good selectivities, while the aldehydes generated from primary alcohols are further oxidized. The process competes with the TBHP catalyzed decomposition. It thus requires the use of excess TBHP and high catalyst loadings to achieve high conversions. However, the low cost of the reagents makes this new protocol convenient for the oxidation of reactive secondary alcohols. The study also suggests that MnO₂ should be proscribed as a reagent to quench excess TBHP in oxidative processes when the synthetic target contains easily oxidizable alcohol functions and when carrying our detailed kinetic monitoring of oxidation processes.     

Effective oxidation of benzylic and aliphatic alcohols with hydrogen peroxide catalyzed by a manganese(III) Schiff-base complex under solvent-free conditions

A variety of alcohols were oxidized efficiently into the corresponding ketones and carboxylic acids in excellent yields with hydrogen peroxide using a manganese(III) Schiff-base complex as a catalyst under solvent-free and mild conditions. The oxidation procedure is very simple and the products are easily isolated in excellent yields.     

Synthese de composes dihydro-2,3 furanniques par hydroboration d'alcools β-acetyleniques

Hydroboration of β-acetylenic alcohols followed by NaOH/H₂O₂ oxidation leads to hemiacetals of γ-aldols which are easily dehydrated to 2,3-dihydrofuran compounds. The reaction gives good yields with hindered alcohols and its stereochemistry may be controlled during the organometallic synthesis of the starting alcohol.     

Tailoring the catalytic performance of sol-gel-encapsulated tetra-n-propylammonium perruthenate (TPAP) in aerobic oxidation of alcohols

Sol-gel nanohybrid silica particles organically modified and doped with the ruthenium species tetra-n-propylammonium perruthenate (TPAP) are highly efficient catalysts for the selective oxidation of alcohols to carbonyl groups with O(2) at low pressure in toluene. The materials are easily prepared by a one-step sol-gel process, and their catalytic performance can be optimised by tailoring the conditions of their synthesis by hydrolytic co-polycondensation of tetramethoxysilane (TMOS) and alkyltrimethoxysilanes R-Si(OMe)(3) in the presence of TPAP. Eventually, heterogeneous catalysts considerably more active than the unsupported perruthenate were obtained, while also being leach-proof and recyclable. The correlation between the materials' activity, surface polarity and textural properties suggests valuable information on the chemical behaviour of sol-gel catalytic materials in oxidation catalysis; this is of interest in view of the importance of efficient solid catalysts for the selective oxidation of alcohols with O(2).