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1.
Ruthenium(II) tris(2,2′-bipyridine) complexes show interesting photochemical properties1. Complexes containing substituents in the 4-and 4′-position of the 2,2′-bipyridine ligand have recently been used in systems which are aimed at the conversion and storage of solar energy2,3. 2,2′-Bipyridine has a long history as a metal-chelating agent4. The use of 4,4′-disubstituted bipyridines as metal-chelating agents so far has been restricted probably because the reported syntheses of these compounds are rather laborious and the yields are low or moderate5–8. 相似文献
2.
Katsuya Maeyama Yasushi Fujiwara Makiya Nishimuro Yasuhiko Yoshida Noriyuki Yonezawa 《合成通讯》2013,43(5):603-609
2,2′‐Alkyl‐disubstituted 4,4′‐oxybiphenols (4) were prepared in good yields through esterification of 4,4′‐oxybiphenol (1), AlCl3‐promoted Fries rearrangement, and AlCl3/NaBH4‐promoted reduction reaction. 相似文献
3.
《合成通讯》2013,43(22):4037-4042
Abstract An improved synthesis of tetrakis(2‐thienyl)methanes, where an aromatic nucleophilic substitution is the key reaction for the introduction of the fourth 2‐thienyl group, has been developed, thus, reaction of tris(2‐thienyl)methyl anion with 2‐fluoro‐5‐cyanothiophene smoothly proceeded to give (5‐cyano‐2‐thienyl)‐tris(2‐thienyl)methane in good yield. Alkaline hydrolysis of the cyano group to carboxylic acid followed by decarboxylation at 180°C in quinoline in the presence of copper(I) oxide afforded the parent tetrakis(2‐thienyl)methane in 50% total yield from the trithienylmethane. 相似文献
4.
《合成通讯》2013,43(8):1377-1382
Abstract An improved three‐steps method for the conversion of N‐benzyl (S)‐3‐hydroxypyrrolidin‐2‐one 6 to (2S,3S)‐3‐hydroxyproline 1 is reported. The key step is the reductive cyanation of 6. The synthesis of 1 constitutes a formal asymmetric synthesis of (2S,3S)‐3‐hydroxyproline betaines 2. 相似文献
5.
Reaction of N,N′‐bis(2‐pyridinyl, 3‐pyridinyl, 4‐pyridinyl, 2‐thiazolyl, 4‐nitrophenyl, and 2‐benzothiazolyl)methanediamines 1a–f with oxalyl chloride in dry dichloroethane in the presence of pyridine affords the corresponding 1,3‐bis (heteroaryl)‐4,5‐imidazolidinediones 3a–f in good to excellent yields. The essential role of pyridine in the reaction mixture is described, and reaction details as well as product characterization is discussed. 相似文献
6.
Ebrahim Soleimani Somayeh Ghorbani Mojtaba Taran Afshin Sarvary 《Comptes Rendus Chimie》2012,15(11-12):955-961
An environmentally friendly and simple method for the synthesis of some 4,4′-(arylmethylene)bis(3-methyl-1H-pyrazol-5-ol) derivatives via a one-pot pseudo five-component reaction of hydrazine hydrate, ethyl acetoacetate and aldehydes in water using pyridine trifluoroacetate or acetic acid at 70 °C is reported. 相似文献
7.
A simple, efficient, mild, and reproducible method for the synthesis of 1‐hydroxy‐2,2,5,5‐tetramethyl‐3‐imidazoline 3‐oxide is described. The method is based on the condensation of 2‐hydroxyamino‐2‐methylpropanal oxime with 2,2‐diethoxypropane in the presence of an equimolar quantity of acetic acid. Cost‐effectiveness of the condensation procedure could be also achieved by replacing 2,2‐diethoxypropane with less expensive 2,2‐dimethoxypropane. 相似文献
8.
9.
Akkirala Venkat Narsaiah 《合成通讯》2013,43(13):1897-1901
Enantiomerically pure (S)‐RO363 was synthesized by using (R,R) Salen Co(III) complex for the resolution of terminal epoxide. The hydrolytic kinetic resolution process was carried out at room temperature in excellent enantioselectivity. The method can be applied for large‐scale preparation of (S) RO363. 相似文献
10.
11.
《Journal of carbohydrate chemistry》2013,32(2-3):95-110
Abstract The α,ω‐diazidoalditol derivatives with erythro, threo, xylo, ribo, D‐arabino, D‐manno, and D‐gluco configuration were efficiently synthesized, respectively, from bis‐ or tris‐cyclic sulfite or peracetylated α,ω‐dibromoalditol intermediates. The cyclic sulfite intermediates has the advantage to lead directly to the free α,ω‐diazido‐α,ω‐dideoxyalditols. 相似文献
12.
An attempted reaction of 4‐bromomethylcoumarin with 2‐hydroxy aromatic aldehyde/2‐hydroxy aromatic ketone at room temperature in the presence of a mild base resulted in the formation of cis‐2′,3′‐dihydro‐3‐hydroxybenzofuranylcoumarins by carbanion addition across the carbonyl carbon. 相似文献
13.
Acyl chlorides reacted with ammonium thiocyanate and carbonic dihydrazide under phase‐transfer catalysis to first afford 2,2′‐bis(acylaminothiocarbonyl)‐carbonic dihydrazides, which further cyclized in the presence of glacial acetic acid to efficiently give 1‐(5′‐acylamino‐1′,3′,4′‐thiadiazol‐2′‐yl)‐4‐acyl‐thiosemicarbazides in high yield. 相似文献
14.
15.
George P. Rizzi 《合成通讯》2013,43(14):1173-1179
A wide variety of 2′-hydroxypolymethoxyacetophenones and propiophenones, e.g. 1a and 1b are used in the synthesis of flavone and ehromone natural products.1 Repeated attempts to prepare 1a and 1b by reacting 1,2,3,5-tetramethoxybenzene 2 with acetyl or propionyl chlorides and AlCl3 in ether2 gave products which were difficult to purify.3 We traced the problem to ring-ethoxy contaminants which were isolated and tentatively identified as 3a and 3b. 相似文献
16.
Synthesis,characterization and properties of 3,3′-diethyl-1,1′-oxydiethylenedicarbonyl bis(thiourea)
Guangyi Liu Heng Ren Jinhua Zhan Jingjing Xiao Hong Zhong 《Research on Chemical Intermediates》2014,40(5):2025-2038
In this paper, 3,3′-diethyl-1,1′-oxydiethylenedicarbonyl bis(thiourea) (DEOECTU), was synthesized by phase transfer catalysis and then characterized by UV, elemental analysis, infrared spectra, mass spectrum, 1H NMR and TGA. DEOECTU properties, such as response to metal ions, adsorption on sulfide mineral surfaces, and hydrometallurgical performance as flotation collectors, were also investigated. The results indicated that DEOECTU reacted chemically with Cu2+ ions through its S and N atoms in the C(=S)–NH–C(=O) group to form a new chelate compound, but no reaction of DEOECTU with Zn2+, Pb2+, Fe3+ or Fe2+ ions was observed. The results of adsorption and flotation experiments demonstrated, that compared to pyrite, sphalerite and galena, DEOECTU exhibited a superior collecting power for chalcopyrite and might attach on chalcopyrite surface by chemisorption. The further theoretical analysis from Pearson’s HSAB view point briefly explained the experimental results of the selective response of DEOECTU to Cu2+ ions and chalcopyrite. 相似文献
17.
Four novel perfluoroalkylated poly(arylene ether)s have been synthesized successfully using four perfluoroalkyl‐activated bisfluoro monomers. These polymers are synthesized through nucleophilic displacement of the fluorine atoms on the benzene ring with 4,4′‐thiodiphenol and are named as 1a, 1b, 1c and 1d, respectively. The polymers obtained by displacement of the fluorine atoms exhibit weight‐average molar masses up to 3.9×104 g · mol?1 in Gel permeation chromatography. These poly(arylene ether)s showed very high thermal stability up to 548°C for 10% weight loss in TGA under nitrogen and high glass transition temperature (Tg) up to 178°C in DSC depending on the repeat unit structures. The glass transition temperatures taken as peak in tan δ in DMA measurements are in good agreement with the DSC Tg values. All the polymers synthesized are soluble in a wide range of organic solvent such as CHCl3, CHCl2, THF, NMP, DMF and toluene. Transparent thin films of these polymers cast from THF exhibited tensile strengths up to 72 MPa, modulus up to 1.69 GPa with low elongation at break depending on their exact repeating unit structures. Rheological properties showed ease of processability of these polymers with no change in melt viscosity with temperature. 相似文献
18.
YIN Han-dong~ 《高等学校化学研究》2004,(5)
IntroductionLinear bidentate N,N′- donor complexes havebeen extensively used in recent years to obtain thepolymeric frameworks with potential applicationprospects in different areas of material sciences,such as electrical conductivity[1] ,magnetism[2 ] ,photomechanical behaviour[3 ] and catalysis[4~ 6] .Among them,4,4′- bipyridine( bpy) has beenproven to be able to form one- dimensional poly-mers[7] ,two- dimensional layers[4] ,and three- di-mensional frameworks exhibiting the interpene-tra… 相似文献
19.
Ashok K. Singh A.K. Jain Anjali Upadhyay K.R.J. Thomas Prerna Singh 《International journal of environmental analytical chemistry》2013,93(8):813-827
The construction and performance characteristics of polymeric membrane electrodes based on neutral ionophore 5,5′‐(5,5′‐(benzo[c][1,2,5]thiadiazole‐4,7‐diyl)bis(thiophene‐5,2‐diyl))bis‐(N1,N1,N3,N3‐tetraphenylbenzene‐1,3‐diamine) (L) for quantification of cadmium ions, are described. Effect of plastisizers dibutylpthalate (DBP), tri‐n‐butylphosphate (TBP), dioctylpthalate (DOP), o‐nitrophenyloctyl ether (o‐NPOE), 1‐chloronaphthalene (CN) and ionic additives sodium tetraphenylborate (NaTPB), potassium tetrakis p‐(chlorophenyl)borate (KTpClPB) was studied. Best performance was obtained with the membrane having a composition L?:?PVC?:?DBP?:?NaTPB?≡?2?:?37?:?59?:?2 (w/w; mg). The membrane electrode exhibits Nernstian response in the concentration range 6.3?×?10?8 to 1.0?×?10??1?mol?L?1 with detection limit 3.6?×?10?8?mol?L?1 and is not affected by H+ ions over a wide pH range 3.0–10.0. The electrode possess a fast response time of 10?s and shelf life period of 3 months. The analytical utility of the proposed electrode has demonstrated by its application in the determination of cadmium in water, medicinal plants and soil samples. It could also be used successfully as an indicator electrode in the potentiometric titration of Cd2+ with EDTA (ethylenediaminetetraacetic acid). 相似文献
20.
The novel, diastereomeric meso- (cis) and (±)- (trans) nitroxides 2,5-dicarboxymethyl-2,5-dimethylpyrrolidine-1-oxyl have been synthesized via a dienolate based strategy. Both optically pure enantiomers of the C 2 symmetric trans diastereomer have been obtained via resolution of the corresponding amine with dibenzoyltartaric acid. 相似文献