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1.
A simple one-pot procedure for the direct conversion of alcohols into azides using TsIm 总被引:1,自引:0,他引:1
A facile and efficient method for one-pot conversion of alcohols into azides using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, alcohols are refluxed with a mixture of NaN3, TsIm and triethylamine in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in DMF affording the corresponding alkyl azides in good yields. This methodology is highly efficient for various structurally diverse alcohols with selectivity for ROH: 1° > 2° > 3°. 相似文献
2.
Mohammad Navid Soltani Rad Ali Khalafi-Nezhad Mohammad Ali Faghihi 《Tetrahedron letters》2007,48(38):6779-6784
A convenient and efficient one-pot preparation of nitriles from alcohols using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, treatment of alcohols with a mixture of NaCN, TsIm and triethylamine in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in refluxing DMF furnishes the corresponding alkyl nitriles in good yields. This methodology is highly efficient for various structurally diverse alcohols with selectivity for ROH: 1° > 2° > 3°. 相似文献
3.
Mohammad Navid Soltani Rad Ali Khalafi-Nezhad Mohammad Ali Faghihi Abolfath Parhami 《Tetrahedron》2008,64(8):1778-1785
A convenient and efficient one-pot N-alkylation of nucleobases from alcohols using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, treatment of alcohols with a mixture of purine or pyrimidine nucleobase, TsIm, K2CO3, and triethylamine in refluxing DMF regioselectively furnishes the corresponding N-alkyl nucleobases in good yields. This methodology is highly efficient for various structurally diverse primary alcohols. 相似文献
4.
Mohammad Navid Soltani Rad Ali Khalafi-Nezhad Somayeh Behrouz Zohreh Amini Marzieh Behrouz 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1658-1671
A facile and highly efficient method for one-pot Beckmann rearrangement of ketoximes into N-substituted amides using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, ketoximes are refluxed with TsIm and Cs2CO3 in the presence of SiO2 as a recyclable catalyst in DMF affording the corresponding amides in high yields. This methodology is highly efficient and regioselective for various structurally diverse ketoximes including symmetrical and unsymmetrical as well as cyclic oximes. The results of quantum mechanical studies used to rationalize the experimental outcomes are discussed. 相似文献
5.
Five coordination compounds Zn(mbmpbi)2Cl2 (1), Zn(mbmpbi)2Br2 (2), Cd(mbmpbi)2Cl2 (3), Hg(mbmpbi)2Cl2 (4) and Hg(mbmpbi)2Br2 (5) were synthesized by the reaction of 1-(p-methoxybenzyl)-2-(p-methoxyphenyl)benzimidazole (mbmpbi) with the corresponding metal halides. The complexes have been characterized by elemental analysis, conductance measurements, FT-IR, 1H NMR and photoluminescence spectral studies. The ligand mbmpbi exhibits the N-benzimidazole coordination. The structures of 3-5 have been determined by single crystal X-ray diffraction. These three complexes are isostructural, crystallizing in the monoclinic system, P2/n space group with a distorted tetrahedral geometry around the metal ion. Zn(II) and Cd(II) complexes show strong blue emission in solid state at room temperature. 相似文献
6.
The interactions between N-(p-chlorophenyl)-N′-(1-naphthyl) thiourea and serum albumin were investigated by fluorescence spectroscopy and UV absorption spectrum under physiological conditions. The results of spectroscopic measurements suggested that N-(p-chlorophenyl)-N′-(1-naphthyl) thiourea should have a strong ability to quench the intrinsic fluorescence of both bovine serum albumin and human serum albumin through static quenching procedure, and the hydrophobic interaction was the predominant intermolecular force stabilizing the complex. Thermodynamic parameter enthalpy changes (ΔH) and entropy changes (ΔS) were calculated according to the Vant’Hoff equation. The binding distances between N-(p-chlorophenyl)-N′-(1-naphthyl) thiourea and the proteins were evaluated on the basis of the theory of Föster energy transfer. In addition, the effects of other ions on the binding constants of complexes were also discussed. Synchronous fluorescence technology was successfully applied to the determination of serum albumins added to the CPNT solution. 相似文献
7.
Ju-Eun Won Jeum-Jong Kim Min-Jung Kim Hyun-A. Chung Yong-Jin Yoon 《Tetrahedron》2007,63(51):12720-12730
(6-Oxo-6H-pyridazin-1-yl)phosphoric acid diethyl esters (3) are efficient and selective coupling agents for equimolar esterification of carboxylic acids and alcohols. Esterification of aliphatic and aromatic carboxylic acids with aliphatic and aromatic alcohols using 3 afforded the corresponding esters chemoselectively in good to excellent yield. 相似文献
8.
A novel flow-injection spectrophotometry has been developed for the determination of molybdenum(VI) at nanograms per milliliter levels. The method is based on the catalytic effect of molybdenum(VI) on the bromate oxidative coupling of p-hydrazinobenzenesulfonic acid with N-(1-naphthyl)ethylenediamine to form an azo dye (λmax = 530 nm). Chromotropic acid (4,5-dihydroxy-2,7-naphthalenedisulfonic acid) acted as an effective activator for the molybdenum(VI)-catalyzed reaction and increased the sensitivity of the method. The reaction was monitored by measuring the change in absorbance of the dye produced. The proposed method allowed the determination of molybdenum(VI) in the range 1.0-20 ng mL−1 with sample throughput of 15 h−1. The limit of detection was 0.5 ng mL−1 and a relative standard deviation for 10 ng mL−1 molybdenum(VI) (n = 10) was 2.5%. The interfering ions were eliminated by using the combination of a masking agent and on-line minicolumn packed with cation exchanger. The present method was successfully applied to the determination of molybdenum(VI) in plant foodstuffs. 相似文献
9.
A stereoselective method has been developed for the synthesis of (Z)- and (E)-allyl iodides from Baylis-Hillman adducts using polymethylhydrosiloxane (PMHS) and iodine in chloroform at room temperature. In addition, the reagent system has been utilized for the iodination of benzylic alcohols selectively. 相似文献
10.
Jon Erik Aaseng 《Tetrahedron》2010,66(52):9790-9797
An enantioselective synthesis of substituted 2-aminotetralins from dihydronaphthalenes in four steps is described. The key step is the Jacobsen’s (diimine)copper-catalyzed asymmetric aziridination of dihydronaphthalenes to the respective aziridines in 33-82% yields and 60-87% enantiomeric excess. The enantioselectivity and the yield were dependent on the properties of the nitrene precursor. pTsNIPh appeared in general to give better results than pNsNIPh. Aziridines were ring-opened in the benzylic position by catalytic hydrogenolysis in quantitative yields, and deprotected in two steps to the respective 2-aminotetralins in 66-85% yields. The synthesis of (S)-2-aminotetralin (>98% ee) and (S)-2-amino-7-methoxytetralin (56% ee) were accomplished in 30 and 52% overall yields, respectively. 相似文献
11.
The heat stable salts (HSS) generated from the gas desulfurization using N-methyldiethanolamine (MDEA) solvents caused many problems such as solution froth, corrosion and fouling of the equipment. In this paper, a specially designed electrodialysis (ED) was employed to remove the heat stable salts from industrial aqueous MDEA solutions. The heat stable salts were successfully removed by adjusting the arrangement of cation- and anion-exchange membranes. To ensure a stable and durative desalination process, appropriate operation parameters such as applied potential and the flow rate were selected as voltage; 9 V and flow rate; 40 L/h. The experimental results show that about 90% of HSS were removed from aqueous solutions of MDEA solvents while the loss ratio is less than 9% under the appropriate conditions. 相似文献
12.
Yurij L. Yagupolskii Andrej V. BezdudnyiLev M. Yagupolskii 《Journal of fluorine chemistry》2002,115(2):129-132
Lithium, sodium and potassium N-(trifluoromethylsulfonyl)trifluoromethanesulfinimidates were obtained by the reaction of the corresponding sulfinimidoyl chloride with alkali metal trimethylsilanolates. The potassium and sodium salts were converted to the free acid, having predominantly the amidic tautomeric structure, CF3S(O)NHSO2CF3, by treatment with concentrated H2SO4 or with H+-cationite. 相似文献
13.
Yukako Saito 《Tetrahedron letters》2005,46(8):1277-1279
A very mild, one-step esterification using nearly equimolar amounts of N-protected amino acids and alcohols, in conjunction with 1-tert-butoxy-2-tert-butoxycarbonyl-1,2-dihydroisoquinoline (BBDI) as a novel condensing reagent is described. 相似文献
14.
Cheng-Kun Lin 《Tetrahedron》2010,66(51):9688-9693
A simple method for the oxidation of primary alcohols to aldehydes using o-iodoxybenzoic acid (IBX) with the addition of stoichiometric acetic acid has been developed. Addition of acetic acid significantly accelerated the reaction rate. Under these conditions, primary aliphatic, benzylic, and allylic alcohols are smoothly converted to aldehydes in high yields (90-97%). 相似文献
15.
Siddaiah Vidavalur Mahaboob Basha GajulaRamu Tadikonda Mangarao NakkaSudhakar Dega Santosh Kumar YadavChristopher Voosala 《Tetrahedron letters》2014
An efficient PTSA catalyzed synthesis of 2-(N-acyl)aminobenzimidazoles and 2-(N-acyl)aminobenzothiazoles has been described using S-ethylated-N-acylthioureas as substrates and polyethylene glycol as solvent. 相似文献
16.
A sensitive and selective method was developed for the determination of N-acetyl-p-aminophenol (APAP) and p-aminophenol (PAP) using poly(3,4-ethylenedioxythiophene) (PEDOT)-modified glassy carbon electrode (GCE). Cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical reaction of APAP and PAP at the modified electrode. Both APAP and PAP showed quasireversible redox reactions with formal potentials of 367 mV and 101 mV (vs. Ag/AgCl), respectively, in phosphate buffer solution of pH 7.0. The significant peak potential difference (266 mV) between APAP and PAP enabled the simultaneous determination both species based on differential pulse voltammetry. The voltammetric responses gave linear ranges of 1.0 × 10−6-1.0 × 10−4 mol L−1 and 4.0 × 10−6-3.2 × 10−4 mol L−1, with detection limits of 4.0 × 10−7 mol L−1 and 1.2 × 10−6 mol L−1 for APAP and PAP, respectively. The method was successfully applied for the determination of APAP and PAP in pharmaceutical formulations and biological samples. 相似文献
17.
Synthesis of new derivatives of 1,5,9,13-tetraaza[16]annulene using 2-substituted vinamidinium salts
New 7,15-dibromo-, 7,15-di(bromomethyl)-, and 7,15-di[4-(bromomethyl)phenyl]-1,5,9,13-tetraaza[16]annulene derivatives are synthesized via the condensation reaction of 2-substituted vinamidinium salts [2-substituted 3-(dimethylamino)-N,N-dimethyl-2-propen-1-aminium salts] with 1,8-diaminonaphthalene in acetonitrile/acetic acid. The ultraviolet spectral behavior of these compounds is examined in DMSO. 相似文献
18.
The electroreductive intramolecular coupling of phthalimides with ketones in the presence of chlorotrimethylsilane gave five- and six-membered trans-cyclized products stereospecifically (>99%). Similar electroreductive intramolecular coupling of phthalimides with aldehydes afforded five-, six-, and seven-membered trans-cyclized products stereoselectively (75-93%). On the other hand, the reductive coupling of N-(oxoalkyl)phthalimides with samarium(II) iodide gave cis-cyclized products stereoselectively (88->99%). 相似文献
19.
Carlos E.D. NazarioAmanda S. Santana Cristiane Y. KawasokoCarlos A. Carollo Gabriela R. HurtadoLuiz H. Viana Sandro L. BarbosaPalimécio G. Guerrero Jr. Francisco A. MarquesVânia B. Dabdoub Miguel J. DabdoubAdriano C.M. Baroni 《Tetrahedron letters》2011,52(32):4177-4181
Sonogashira cross-coupling reactions involving (E)-iodo vinyl stannanes and terminal acetylenes were carried out in the presence of Pd(PPh3)4, CuI and several amines, affording (Z)-tributylstannyl enynes in moderate to good yields (62-91%). Utilizing the catalytic system containing Pd(PPh3)4 (5%), CuI (10%), and TBAOH (40% in aqueous media) as activator, better yields (72-91%) and lower reaction times were achieved. 相似文献
20.
A series of 3-(N-substituted)-aminoquinolin-2(1H)-ones have been synthesized by the palladium-catalyzed C-N coupling reaction starting from 3-bromoquinolin-2-(1H)-ones. Various nucleophiles including amines, amides, sulfonamides, carbamates and ureas have been used successfully. In all the cases, the reactions take place rapidly in 1,4-dioxane and proceed in good to excellent yield using palladium acetate as a catalyst, Xantphos as a ligand and Cs2CO3 as a base. 相似文献