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1.
Regioselective copper(I)-catalyzed C–H hydroxylation/C–S coupling of aryl thiols with vinyl halides was developed. Starting from substituted aryl thiols and vinyl halides, various 2-(styrylthio)phenol derivatives were efficiently prepared. The application of the synthetic methodology to generate the bioactive organic intermediate was also exemplified. 相似文献
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Triazene‐substituted arylboronic esters were prepared readily from the corresponding aryl magnesium derivatives and shown to function as a new class of donor–acceptor‐substituted coupling reagents. The selective functionalization of these aromatic derivatives led to a wide variety of terphenyl derivatives in which the original bifunctional unit (often further substituted with another functional group) formed the central aromatic ring. The functionalized terphenyl derivatives were formed in two efficient cross‐coupling steps from the triazene‐substituted boronic esters: Suzuki cross‐coupling with an aryl halide was followed by BF3?OEt2‐induced palladium‐catalyzed coupling of the diazonium salt generated in situ from the triazene with an arylboronic acid. 相似文献
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l-Benzoxepino(3, 4-b)quinolin-l3(6H)-one and its halogen,alkyl, alkoxy derivatives Va'-d' and 1-benzothiepino(3,4-b}-quinolin- 13 ( 6H)-one Vf, and its alkyl derivatives Vg, weresynthesized through cyclization of 2-(substituted phenoxymethyl)-3-quinolinecarboxylic acids Va-d and 2-[ (un)substituted phen-ylthiomethyll-3-quinolinecarboxylic acids IVf-g in the presence ofpolyphosphoric acid.The acids IV were obtained from the corresponding ethyl-esters @ whcih were prepared through refluxing ethyl 2-bromo-methyl-3-quinolinecarboxylate(1) with substituted phenol or (un)substituted thiophenol in the presence of NaOEt.The compound Vg, was allowed to react with NBS, KaBH4, NH2OH-HCl to give compounds VII , VIII, and IX, respectively.The structures of 24 new compounds have been confirmed by elemental analysis, IR and 1H NMR. 相似文献
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Synthesis and Characterization of New Xanthene Derivatives,and Their Electrochemical Study 下载免费PDF全文
This work investigated the synthesis of biphenyl‐3,3′,4,4′‐tetracarboxylic dianhydride and benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride derivatives ( 3a – e and 6a – e ) with different substituted phenols via Friedel‐Crafts acylation reaction in the presence of dilute sulfuric acid. Dianhydride derivatives with 3‐N,N′‐dimethylamino phenol ( 3d and 6d ) and resorcinol ( 3e and 6e ) have been found to be highly fluorescent. The structures of all newly synthesized compounds were confirmed by the chromatographic, spectral and elemental data. Electrochemical study was done to determine to band gap energy, LUMO and HOMO levels energy. Band gap and LUMO energy levels were found to be lowest in xanthene derivatives substituted with 3‐N,N′‐dimethylamino group having value 2.24 and 4.85 eV respectively. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(51):16536-16540
The coupling of ortho ‐ and para ‐phenols with secondary and tertiary boronic esters has been explored. In the case of para ‐substituted phenols, after reaction of a dilithio phenolate species with a boronic ester, treatment with Ph3BiF2 or Martin's sulfurane gave the coupled product with complete enantiospecificity. The methodology was applied to the synthesis of the broad spectrum antibacterial natural product (−)‐4‐(1,5‐dimethylhex‐4‐enyl)‐2‐methyl phenol. For ortho ‐substituted phenols, initial incorporation of a benzotriazole on the phenol oxygen atom was required. Subsequent ortho ‐lithiation and borylation gave the coupled product, again with complete stereospecificity. 相似文献
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Nilesh D. Parmar Sanjay D. Hadiyal Vimal H. Kapupara Jaydeep N. Lalpara Hitendra S. Joshi 《Journal of heterocyclic chemistry》2021,58(7):1437-1445
We report here the synthesis of different substituted tetrahydropyridopyrazine derivatives. This approach of synthesis has been designed in a way that in first simple chloro-amine coupling as an alternative of Buchwald coupling followed by heterogeneous hydrogenation of nitro to give amine and further cyclization of this amine with carboxylic acid was accomplished in a single process with the help of continuous flow hydrogenation reactor. This processing was a generation of hydrogen (in situ) by electrolysis of water molecule and using a pre-packed cartridge of a palladium catalyst. In a further step, LAH was used to reduce lactam to a yielding product as tetrahydropyridopyrazine (TPP) scaffold. Final adducts were obtained using substituted benzoyl and sulfonyl derivatives. 相似文献
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Le Paih J Dérien S Demerseman B Bruneau C Dixneuf PH Toupet L Dazinger G Kirchner K 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(4):1312-1324
The reaction of propargylic alcohols with carboxylic acid, or phenol derivatives, in the presence of the precatalyst [RuCl(cod)(C5Me5)] leads selectively to a variety of alkylidenecyclobutenes through head-to-head dimerization of propargylic alcohol. The first step is the formation of a cyclobutadiene-ruthenium intermediate resulting from the head-to-head coupling of two molecules of propargylic alcohol. On protonation with strong acids (HPF6, HBF4) dehydration of the cyclobutadiene complex leads to formation of an alkylidenecyclobutenyl-ruthenium complex. The X-ray structure of one such complex, [RuCl(C5Me5)(eta4-R'CCH--CH--C=CR2)] (R'=cyclohexen-1-yl, CR2 = cyclohexylidene) has been determined. Carboxylate is added at the less substituted carbon of the cyclic allylic ligand. DFT/B3 LYP calculations confirm that the intermediate arising from head-to-head coupling of alkyne to the RuClCp* species yields the cyclobutadiene-ruthenium complex more easily with propargylic alcohol than with acetylene. 相似文献
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Haile Tecle Stephen C. Bergmeier Lawrence D. Wise Fred M. Hershenson Linda L. Coughenour Thomas G. Heffner 《Journal of heterocyclic chemistry》1989,26(4):1125-1128
Synthesis of alkyl substituted derivatives of 3-(1-propyl)3-piperidinyl)phenol ( 3-PPP ), 2–8 , was carried out in an attempt to improve on the pharmacodynamic properties of 3-PPP. No significant improvement was attained. 相似文献
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The influence of ring size ( 5 or 6 ), chain length ( 1 , 2 or 3 ) and bulkiness of N‐aryl substituents in amine‐bridged bis(phenol) ligands ( 1 , 2 , 3 ) on palladium‐catalyzed aqueous C‐C coupling reactions were revealed. The homocoupling of arylboronic acid can be completed in neat water with the aid of a catalytic amount of p‐toluenesulfonyl chloride (TsCl) in a very short time under anaerobic or aerobic conditions. Interestingly, the same catalytic system was efficient for Suzuki–Miyaura reaction in aqueous acetone under aerobic conditions in the absence of TsCl. The crystal structures of ligand 1 and three unsymmetrical fluorine‐substituted biaryl derivatives were also reported. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Papori Goswami 《合成通讯》2013,43(13):2271-2278
A wide range of substituted coumarin derivatives were synthesized by refluxing in acetonitrile, ethyl acetoacetate, and ethyl benzoyl acetate with a wide range of structurally diverse phenol derivatives within a short reaction time with a catalytic combination of pyridine dicarboxylic acid as organocatalyst and nanocrystalline ZnO. 相似文献
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Dr. Eduardo Busto Dr. Robert C. Simon Prof. Dr. Wolfgang Kroutil 《Angewandte Chemie (International ed. in English)》2015,54(37):10899-10902
Readily available substituted phenols were coupled with pyruvate in buffer solution under atmospheric conditions to afford the corresponding para‐vinylphenol derivatives while releasing only one molecule of CO2 and water as the by‐products. This transformation was achieved by designing a biocatalytic system that combines three biocatalytic steps, namely the C? C coupling of phenol and pyruvate in the presence of ammonia, which leads to the corresponding tyrosine derivative, followed by deamination and decarboxylation. The biocatalytic transformation proceeded with high regioselectivity and afforded exclusively the desired para products. This method thus represents an environmentally friendly approach for the direct vinylation of readily available 2‐, 3‐, or 2,3‐disubstituted phenols on preparative scale (0.5 mmol) that provides vinylphenols in high yields (65–83 %). 相似文献
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Bharat B. Kashid Anil A. Ghanwat Vijay M. Khedkar Balasaheb B. Dongare Mubarak H. Shaikh Prathmesh P. Deshpande Yogesh B. Wakchaure 《Journal of heterocyclic chemistry》2019,56(3):895-908
A series of novel 2‐substituted benzimidazole and benzoxazole derivatives as a potential antimicrobial and antioxidant agent were synthesized via coupling of N‐methyl‐o‐phenylenediamine or 2‐amino‐phenol with aromatic aldehyde and acid in the presence of polyphosphoric acid as an efficient catalyst as well as solvent by conventional method in short reaction times with excellent yield. The newly synthesized benzimidazole and benzoxazole derivatives were evaluated for antimicrobial and antioxidant activity and exhibited excellent to good activities compared to the standard drugs. Furthermore, the theoretical predictions based on molecular docking against microbial DNA gyrase could provide an insight into the plausible mechanism of action and establish a link between the observed antimicrobial activity and the binding affinity shedding light on specific thermodynamic (bonded and nonbonded) interactions governing the activity. Furthermore, the synthesized compounds were analyzed for absorption, distribution, metabolism, and excretion properties and exhibited potential properties to build up as good oral drug candidates. 相似文献
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Preparation and Regioselective Metalation of Bis(trimethylsilyl)methyl‐Substituted Aryl Derivatives 下载免费PDF全文
Veronika Werner Thomas Klatt Masaya Fujii Jenifer Markiewicz Prof. Dr. Yitzhak Apeloig Prof. Dr. Paul Knochel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(27):8338-8342
A range of bis(trimethylsilyl)methyl‐substituted aryl derivatives was prepared by using a Kumada–Corriu cross‐coupling reaction. The regioselective metalation of the resulting bis(trimethylsilyl)methyl‐substituted aryl derivatives bearing this bulky silyl group allowed the generation of functionalized aromatics. A regioselective switch in the presence or in the absence of the bis(trimethylsilyl)methyl group has been demonstrated. Furthermore, this silyl group was converted into a formyl group or a styryl group, enhancing the scope of application of such bis(trimethylsilyl)methyl‐substituted arenes. 相似文献
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Triphenylene derivatives with six peripheral chains can make excellent discotic liquid crystals showing great promise in electronic devices. Vanadium oxytrichloride was found to be a novel reagent for the preparation of various triphenylene derivatives. Symmetrically substituted hexaalkoxytriphenylenes were obtained from o-dialkoxybenzenes by oxidative trimerization with VOCl3 in high yields. Oxidative coupling of a 3,3',4,4'-tetraalkoxybiphenyl with 1,2-dialkoxybenzenes yielded unsymmetrically substituted derivatives of triphenylene; a direct coupling of a 3,3',4,4'-tetraalkoxybiphenyl with alkoxyphenol produced monofunctionalized triphenylenes. 相似文献
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《液相色谱法及相关技术杂志》2012,35(19):3457-3473
Abstract The retention characteristics of 29 phenol derivatives were determined on a porous graphitized carbon column in unbuffered acetonitrile—water and methanol—water eluent mixtures at various organic phase concentrations. Each phenol derivative showed symmetric peaks in each eluent without buffers. Good linear correlations were found between the log k' value and the organic mobile phase concentration in the eluent. Principal component analysis indicated that methanol and acetonitrile expose different selectivities. Stepwise regression analysis proved that the retention of ring—substituted phenol derivatives is mainly governed by the sterical parameters, electron-withdrawing power and hydrogen donor capacity of substituents. According to the results of Free-Wilson analysis, the substituents with large steric parameters, strong electron-withdrawing power and hydrogen donor capacity have the highest impact on the retention. The lipophilicity of phenol derivatives did not affect significantly the retention, although the eluents were typical reversed-phase eluents. 相似文献
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The asymmetric coupling of various phenol or aniline derivatives with bulky aryllead triacetates was thoroughly investigated using optically active amines, including strychnine and brucine. We found that conformationally restricted tertiary amines, as well as lithium aryloxides and molecular sieves, are essential for accelerating the rate of phenol coupling. Consequently, the reaction can be carried out at a low temperature (-40 to -20 degrees C) and gives a high degree of diastereo- and enantioselectivity. In contrast to the effectiveness of lithiation in phenol coupling, magnesation of anilines was a critical technique for aniline coupling with aryllead triacetates. Using these coupling methods, a diverse set of di-, tri, and polyaryl compounds with axial chirality can be easily obtained, and these should be useful for the construction of a variety of aryl-aryl frameworks involved in metal ligands, natural products, and artificial helical polymers. 相似文献
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The scope of the cycloaromatization of propargylic ethers was explored using operationally simple air- and moisture-insensitive conditions. Highly substituted phenol derivatives were obtained in high yields. Mechanistic experiments indicate that the reaction occurs by an electrocyclization followed by 1,3-proton transfer. 相似文献