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1.
[reaction: see text] Ytterbium triflate was shown to be an effective catalyst in promoting the synthesis of either isopropyl esters or free alpha-hydroxy-arylacetic acids from substituted aromatic glyoxals and aryl methyl ketones, respectively. The reaction to provide acids starting from differently substituted ketones was carried out by an environmentally friendly method using an aqueous medium as a solvent and giving the adducts in 78-99% yield without any further purification after the usual workup. 相似文献
2.
Hoda Yahyavi Majid M. Heravi Mohammad Mahdavi Alireza Foroumadi 《Tetrahedron letters》2018,59(2):94-98
The simple and facile strategy for the synthesis of 2,3-disubstituted-chromeno[4,3-b]pyrrole-4(1H)-ones has been established. This method describes the Kornblum oxidation reaction of acetophenones, followed by the Knoevenagle treatment of the resulted (het)arylglyoxals with active methylene compounds and consequently iodine-activated Michael type reaction with 4-amino coumarin in a one-pot manner to afford disubstituted chromeno[4,3-b]pyrrole-4(1H)-one derivatives. 相似文献
3.
A palladacycle-catalyzed tandem Heck-intramolecular aza-Michael reaction protocol has been developed for the one-pot synthesis of 1-substituted isoindolines from N-unprotected 2-bromobenzylamines and acrylates with high yields. 相似文献
4.
An easy one-pot tandem reaction catalyzed by a chiral secondary amine for the synthesis of optically active oxazine derivatives has been performed and the corresponding substituted benzo[d]pyrido[2,1-b][1,3]oxazine derivatives were afforded in generally high yields (up to 99%) and excellent enantioselectivities (up to >99%). 相似文献
5.
Some novel 2-oxo-acetamidines were synthesized via one-pot three-component reaction of acetophenones, secondary amines and anilines in presence of CuI as catalyst. The reaction involved in a oxidation process of C (sp3)H bonds of acetophenones in presence of air followed by aminations, and products were obtained in good to excellent yields (70–82%) in simple work-up procedure. 相似文献
6.
A convenient one-pot synthetic method for the formation of alkyl aryl sulfides from various alkyl halides and lithium aryl thiolates that are prepared in situ by direct halogen-lithium exchange is reported. In particular, the method overcomes many of the problems encountered in previous reports; it is very quick, catalyst-free, and does not involve use of unstable aryl thiols. 相似文献
7.
The palladium-catalyzed sequential one-pot N-arylation-carbo-amination-C-arylation of O-homoallylhydroxylamines with two different aryl bromides provides rapid entry to differentially arylated N-aryl-3-arylmethylisoxazolidines in good yields with excellent diastereoselectivity. The obtained isoxazolidines can be reductively cleaved to cis-N-aryl-beta-amino alcohols in short times and in high yields at room temperature. 相似文献
8.
A one-pot synthesis of unsymmetrical tertiary amines from amides, lactams and urethanes has been developed. The reaction is general for all cases examined with the exception of N-aryl containing examples, which are not accessible by this method. 相似文献
9.
The reaction of benzenediazonium carboxylate with chloroform in refluxing tetrahydrofuran afforded 5,5,5-trichloropentyl phenyl ether in 61% yield along with benzoic acid (7%). When dichloroacetonitrile was used as a reactant, 5,5-dichloro-5-cyanopentyl phenyl ether was obtained in 65% yield. Reactive benzyne derived from diazonium carboxylate initially reacted with THF to give a dipole intermediate, which further reacted with chloroform or dichloroacetonitrile to give ring opened products. 相似文献
10.
Keng Yoon Yeong Mohamed Ashraf Ali Chee Wei Ang Soo Choon Tan Hasnah Osman 《Tetrahedron letters》2014
A facile method to synthesize various 1,2-disubstituted benzimidazoles is developed. It is suggested that formation of a Meisenheimer adduct between the substrate, amine, and solvent aids the N-arylation process. The generality of the protocol is demonstrated by the efficient reactions involving numerous substituents ranging from electron-withdrawing groups to electron-donating groups. 相似文献
11.
A one-pot base-mediated reaction of azides and β- or α-vinyl bromides has been reported. The effects of bases and solvents have been investigated in the process. A variety of 1,5-disubstituted triazoles were prepared in low to good yields. Further studies reveal that the corresponding alkynes were produced as intermediates via elimination reaction. Under the same reaction conditions, the reactions of alkyl alkynes with phenyl azide would give 1,5-disubstituted 1,2,3-triazoles. 相似文献
12.
An efficient, convenient, high-yielding synthesis of α-amino aryl ketones is described, involving the one-pot deprotonation-transmetallation-arylation of a Weinreb amide while retaining chirality of the original amide. 相似文献
13.
Krishnamurthy Rameshbabu 《Tetrahedron letters》2007,48(27):4755-4760
A polycyclic aromatic compound, anthracene, was covalently connected through a methylene bridge via Friedel-Crafts alkylation reaction. Thus, a highly fluorescent anthracene polymer (PMAn) linked by a methylene unit was prepared in one step to produce a conjugated-nonconjugated spacer-type polymer through its reaction with chloromethyl methyl ether (CME) and FeCl3 at 0 °C. The resultant polymer was soluble in organic solvents and showed significantly higher fluorescence (quantum yield = 0.80) compared to monomeric anthracene, 9-methylanthracene, in chloroform solution. Fluorescent thin films of PMAn as solid media were prepared with high film uniformity. The emission of the film was extinguished when the film was exposed to a UV source, due to the photodimerization of anthracene unit. A fluorescent gap electrode pattern was formed on the polymer film-forming average step depth of 8 nm and 14 nm, after 30 and 60 min irradiation with a UV light, respectively. The photo patternable fluorescent polymer afforded a convenient method of image formation and patterning. 相似文献
14.
B. MadhavS. Narayana Murthy B.S.P. Anil KumarK. Ramesh Y.V.D. Nageswar 《Tetrahedron letters》2012,53(30):3835-3838
The first ever tandem one-pot synthetic protocol for the synthesis of thiazoles/selenazoles from alkynes via the formation of 2,2-dibromo-1-phenylethanone is reported. The reaction is catalyzed by β-cyclodextrin in aqueous medium and resulted in good yields. 相似文献
15.
A new Vilsmeier-type reaction is suggested for the synthesis of novel indocarbocyanine pH sensors, which are fluorescent when protonated but nonfluorescent upon proton abstraction. These sensors show significant ratiometric UV-visible as well as fluorescence spectral changes upon subtle variation of pHs with pKa values near neutral. 相似文献
16.
Nair V Sethumadhavan D Nair SM Rath NP Eigendorf GK 《The Journal of organic chemistry》2002,67(21):7533-7536
Highly substituted tropone derivatives were obtained as a result of SnCl4-catalyzed cycloaddition of 3-methoxy-substituted o-benzoquinones with aryl acetylenes and subsequent rearrangement of the adducts with concomitant decarbonylation. 相似文献
17.
The one-pot three-component condensation of a beta-ketoester, ammonia and an alkynone in the presence of a Br?nsted or Lewis acid or Amberlyst 15 ion exchange resin provided 2,3,6-trisubstituted or 2,3,4,6-tetrasubstituted pyridines directly in good yield and with total regiocontrol. 相似文献
18.
B.S.P. Anil KumarB. Madhav K. Harsha Vardhan ReddyY.V.D. Nageswar 《Tetrahedron letters》2011,52(22):2862-2865
A variety of quinoxalines were synthesized via tandem one-pot procedure for the first time in water medium. The key strategy was the in situ preparation of α-halo-β-keto esters by the reaction of N-bromo succinimide with β-keto esters and further condensation with phenylene diamines. This novel eco-friendly approach offers an easy, efficient, and mild synthesis of highly substituted quinoxalines in good yields. 相似文献
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20.
Hollmann D Bähn S Tillack A Beller M 《Chemical communications (Cambridge, England)》2008,(27):3199-3201
Highly selective alkyl transfer processes of mono-, di- and trialkyl amines in the presence of the Shvo catalyst have been realized; in addition, a general method for N-alkylation of aniline with di- and trialkyl amines is presented. 相似文献