共查询到20条相似文献,搜索用时 15 毫秒
1.
Mahmood Tajbakhsh Moslem-Mansor Lakouraj Mohammad-Hosein Gholami Farhad Ramzanian-Lehmali 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1731-1736
Deprotection of phenylhydrazones and semicarbazones to their parent aldehydes and ketones in high yields has been carried out using caro's acid supported on silica gel as a selective oxidant under mild conditions. 相似文献
2.
Ardeshir Khazaei Ebrahim Mehdipour Soleiman Yadegari 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):437-441
POLY [N-(4-PYRIDINIUM DICHROMATE)-P-STYRENE SULPHONAMIDE] is readily prepared. It is a stable, mild, and efficient oxidizing reagent that can be used for oxidation of different alcohols to their corresponding carbonyl compounds in approtic solvents. This polymer can be synthesized from the reaction between poly [N-(4-pyridyl)-p-styrene sulphonamide] and CrO 3 in a minimum amount of water. The latter polymer was prepared by free radical polymerization of [N-(4-pyridyl)-p-styrene sulphonamide] by using azobis(isobutyronitrile) (AIBN) as an initiator. N-(4-pyridyl)-p-styrene sulphonamide was synthesized from commercial 4-vinyl benzene sulphonic acid sodium salt and 4-amino pyridine. POLY [N-(4-PYRIDINIUM DICHROMATE)-P-STYRENE SULPHONAMIDE] can oxidize both aliphatic and aromatic alcohols in good yields at a temperature of 38°C and in CH 2 Cl 2 as solvent. One advantage in using this reagent is the mild condition of the reaction system. The synthesized compounds including polymeric reagent and carbonyl compounds were identified by HNMR and IR spectroscopy. 相似文献
3.
《合成通讯》2013,43(21):3383-3393
Oxidation of alcohols to carbonyl compounds has been carried out by utilization of Jones reagent supported on silica gel (SJR). The SJR procedure has advantages over traditional Jones oxidation procedure. This procedure is safer to carry out and simplified workup by allowing organic media. 相似文献
4.
Ardeshir Khazaei Abbas Amini Manesh Amin Rostami 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2483-2486
A new method for the direct conversion of various oximes into aldehydes and ketones by treatment with N-bromosaccharin is described. N-bromosaccharin can be used for an effective, selective and mild oxidizing agent for the regeneration of carbonyl compounds from oximes in good yield. 相似文献
5.
M. Tajbakhsh M. M. Lakouraj Vida Khojasteh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):463-468
Efficient oxidation of 1,4-dihydropyridines with Caro's acid on silica gel is achieved under nonaqueous conditions and in a domestic microwave oven. The reactions under microwave irradiation were shorter in duration and higher in yields than the reactions in conventional method, confirming the potentiality of microwave heating in aromatization of Hantzsch 1,4-dihydropyridines. 相似文献
6.
Peyman Salehi Mohammad Ali Zolfigol Leila Bazaz Tolami 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1777-1781
1,4-Diazabicyclo[2.2.2]octane-di-N-oxide-di-perhydrate[3pc] selectively oxidizes thiols to disulfides in acetonitrile in good yields. The method is generally useful for a wide variety of thiols. 相似文献
7.
随着人们对吸附态有机分子光谱性质的研究的不断深入,光化学中的一个重要方面——表面光化学,也得到了很大的发展。在固体表面上,人们观察到了许多与溶液中不同的现象。这主要是由于固体表面上常常表现出某种特有的吸附特性,从而对被吸附物质的能级状态和分子结构产生影响,进而改变了它们的反应性能,这类报道已有很多[1]。 相似文献
8.
Peyman Salehi Minoo Dabiri Ali Zolfigol Ali Bodaghi Fard 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1113-1121
The nucleophilic ring opening reactions of epoxides by aliphatic alcohols and water are achieved efficiently in the presence of catalytic amounts of silica sulfuric acid with high degree of regioselectivity. The catalyst is reusable and can be applied several times without any decrease in the yield of reactions. 相似文献
9.
10.
Mohammad Ali Zolfigol Farhad Shirini Khosrow Zamani Efat Ghofrani Satar Ebrahimi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2177-2182
Silica phosphoric acid was prepared via reaction of silica chloride (I) and phosphoric acid. Thiols can be readily converted to their corresponding thionitrites with a combination of silica phosphoric acid (II), wet SiO 2 , and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur–nitrogen bond of the unstable thionitrite and subsequent coupling of the resultant thiyl radicals. 相似文献
11.
M. M. Lakouraj M. Tajbakhsh V. Khojasteh M. H. Gholami 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2645-2651
Efficient conversion of acetals, ketals, and diacetates to carbonyl compounds is described using Caro's acid supported on silica gel. The deacetalization reactions are carried out in acetonitrile at room temperature. Reaction of diacetates is performed in refluxing dichloromethane, and their parent carbonyl compounds are obtained in good-to-excellent yields. 相似文献
12.
Hossein Eshghi Parvaneh Shafieyoon 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2149-2152
A facile and efficient method for the preparation of tetrahydropyranyl ethers from alcohols is improved in solvent-free media. These reactions are catalyzed by P2O5 and afford various tetrahydropyranyl ethers in shorter reaction time, with good to excellent yields (75–95%) at room temperature. This method is also compatible with substrates containing acid-sensitive functional groups. 相似文献
13.
制备了一系列V,Ag,Ni原子比不同的三元氧化物,应用TPD-MS技术研究了样品表面氧的性质,并测定了甲苯选择性氧化生成苯甲醛的催化活性。实验结果表明,样品表面存在有多种吸附的氧物种。在脱附温度<900℃:当Ni含量对Ag(或V)的原子比为0.25或0.50时,仅在低温处出现有表面的O^-和O^2^-两种氧物种的脱附峰;当Ni含量对Ag(或V)的原子比增高到>0.75时,除有表面的O^-和O^2^ 相似文献
14.
Iraj Mohammadpoor-Baltork Hamid Reza Memarian Kiumars Bahrami 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2315-2321
A variety of aliphatic, aromatic, and heteroaromatic thiols were rapidly and cleanly converted to their corresponding disulfides in excellent yields using n-butyltriphenylphosphonium dichromate (BTPPDC) in acetonitrile solution under solvent-free conditions and microwave irradiation. Selective oxidation of thiols in the presence of other oxidizable functional groups, such as alcohol and sulfide, is a noteworthy advantage of this method. 相似文献
15.
微波条件下V2O5/TiO2低温选择氧化甲苯制苯甲酸 总被引:13,自引:0,他引:13
在微波辐射条件下,考察了甲苯选择氧化过程中催化剂床层温度、O2/甲苯比、原料气总空速、V2O5担载量和添加氧化物助剂等条件对V2O5/TiO2催化剂活性的影响.结果表明,在微波作用下,当床层温度在250℃,O2/甲苯摩尔比6和原料气总空速10000h-1时,1%MoO3-8%V2O5/TiO2上的苯甲酸和苯甲醛的收率分别达到41%和14%.与传统加热的催化过程相比,苯甲酸和含氧化物的收率均有较大的提高.还初步探讨了微波对催化剂活性的影响. 相似文献
16.
环戊烷选择性氧化用VPO催化剂的合成新方法 总被引:5,自引:1,他引:4
研究了VPO催化剂时还原溶剂对VPO的结构及催化性能的影响,VPO的合成方法如下:(1)V2O5与H3PO4反应生成磷酸钒;(2)用不同的还原溶剂还原磷酸钒得到VPO催化剂前身;(3)活化VPO催化剂前身,研究的还原溶剂有;异丁醇,异丁醇-苯甲醇,异丁醇-石油醚和正己醇。结果表明,使用异丁醇-石油醚作还原溶剂,只能生成VOHPO4.0.5H2O晶体;使用其它溶剂则会生成VO(H2PO4)2和VOH 相似文献
17.
采用共沉淀法制备了一系列磷钼体系多组分催化剂P1.33-dMo12VaCubSbcAsdK1.5Ox/SiC(0.0≤a,b,c,d≤0.50)。利用XRD、FTIR、DSC、ESR等方法对催化剂的结构与性质进行了研究。XRD、FTIR的研究结果表明,合成的样品为具有Keggin杂多阴离子结构的磷钼杂多化合物。DSC,ESR测试结果表明催化剂具有较好的稳定性。同时考察了催化剂组分对异丁烷催化氧化性能的影响,结果表明,适量地引入V、As、Cu、Sb都能提高MAA(甲基丙烯酸)的选择性和MAA+MAL(甲基丙烯醛)的收率。催化剂P1.13Mo12V0.25Cu0.25Sb0.25As0.2K1.5Ox/SiC在360 ℃、常压、进料组成异丁烷:空气=1∶2(mol)、空速3 600 h-1条件下,异丁烷转化率10.7%,MAA+MAL的收率为6.8%。 相似文献
18.
Mohammad Ali Zolfigol Peyman Salehi Morteza Shiri 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2273-2277
H 3 PMo 12 O 40 · xH 2 O was found to be an effective catalyst for the preparation of bis-indolyl derivatives from indole and aromatic, aliphatic, heterocyclic aldehydes or ketones in ethanol at room temperature. 相似文献
19.
《合成通讯》2013,43(23):3565-3574
ABSTRACT Selective mono nitration of Aromatic hydrocarbons and benzylic oxidations can be achieved in high yield using reusable catalyst/reagent system consisting of bentonite clay and dilute HNO3 under relatively mild experimental conditions. The dual behavior of the catalyst reagent system is utilized for the regioselective synthesis of a variety of industrially important compounds. 相似文献