共查询到20条相似文献,搜索用时 15 毫秒
1.
Manas Chakrabarty Sulakshana Karmakar Ratna Mukherjee Shiho Arima Yoshihiro Harigaya 《Monatshefte für Chemie / Chemical Monthly》2009,140(4):375-380
Abstract 1-Alkyl/phenyl-2-arylbenzimidazoles have been synthesized in very good to excellent yields by a one-pot condensation of N-alkyl/phenyl-o-phenylenediamines with aryl aldehydes in water at room temperature using cetylpyridinium bromide as a cheap and eco-friendly
catalyst.
Graphical abstract
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2.
A facile one-pot C-benzylation of various sodium enolates derived from methyl malonate, beta-ketoesters, a beta-cyanoester, a beta-cyanosulfone, ketones and a carboxylic ester is reported. Reaction of alkoxydiphenylsulfonium salts formed by treating various benzyl alcohols with diphenyl sulfide bis(trifluoromethanesulfonate) (derived from trifluoromethanesulfonic anhydride and diphenyl sulfoxide) proceeded smoothly, and the corresponding C-benzylated products were afforded in good to high yields. 相似文献
3.
Matthieu DesrosesKrzysztof Wieckowski Marc StevensLuke R. Odell 《Tetrahedron letters》2011,52(34):4417-4420
A rapid, mild, and high yielding protocol for the Fischer indolization of arylhydrazines with T3P® under microwave irradiation is described. Significant features of this method include short reaction times and preparative ease. 相似文献
4.
A one-pot, synthesis of N-arylsulfonyl-2-iminocoumarins is developed at ambient temperature by the reaction of 2-hydroxybenzaldehydes, arylacetonitriles, and aryl sulfonyl chlorides using DABCO as a base in a bio-mass-derived green solvent 2-MethylTHF. A simple telescoped process in which 2H-chromen-2-imines are formed in situ by the condensation of 2-hydroxybenzaldehyde and arylacetonitriles. The formed imines are further reacted with arylsulfonyl chlorides in a one-pot approach to obtain the target compounds. This protocol provides access to 3-aryl-N-arylsulfonyl-2-iminocoumarins in a practical and environmentally benign way avoiding cumbersome steps of intermediate syntheses and purifications. 相似文献
5.
Xizhen Zhu Kevin D. Kreutter Huaping Hu Mark R. Player Micheal D. Gaul 《Tetrahedron letters》2008,49(5):832-834
A novel reagent combination, Tf2O/Na2CO3·1.5H2O2, has been developed for the oxidation of highly electron deficient pyridines to their corresponding N-oxides. The N-oxidation reaction, utilizing the in situ generated peracid, proceeds under mild conditions that allow for a number of functional groups and substitution patterns on the pyridine ring. 相似文献
6.
《Mendeleev Communications》2020,30(2):238-240
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7.
An efficient synthesis of 9,10-disubstituted phenanthrenes is described in this Letter. These novel useful building blocks were obtained in a one-pot reaction including Suzuki-Miyaura cross-coupling followed by a Dieckmann-Thorpe ring closure under microwave irradiation. The selection of the appropriate reagents and the optimal reaction conditions to isolate the intermediate biphenyl compound or the final substituted phenanthrenes in high yields will be discussed in this Letter. 相似文献
8.
Keith R. Hornberger George M. Adjabeng Hamilton D. Dickson Ronda G. Davis-Ward 《Tetrahedron letters》2006,47(30):5359-5361
A one-pot synthesis of disubstituted benzimidazoles from 2-nitroanilines is described. Hydrogenation of N-substituted 2-nitroanilines with palladium on carbon as catalyst in the presence of trimethyl orthoformate and catalytic pyridinium p-toluenesulfonate (PPTS) at room temperature provided good to excellent yields of the corresponding disubstituted benzimidazoles. 相似文献
9.
Audrey MartinezJimmy Sélambarom 《Tetrahedron letters》2011,52(13):1444-1447
A convenient and general one-pot, two-step protocol to prepare both N-acyl-1,3-thiazolidines and N-acyl-1,3-oxazolidines from formaldehyde, fatty acyl chlorides, and natural α-amino acids has been performed for the peculiar case of formaldehyde. In the presence of triethylamine to promote both the ring-forming process and the amide bond formation, subsequent addition of the acyl donor proved to be efficient to trap the preformed stable formaldehyde-derived 1,3-thiazolidine or the transient 1,3-oxazolidine using an appropriate ratio of formaldehyde. 相似文献
10.
An expedient one-pot sequential five-component synthesis of highly substituted pyrrolidine heterocycles involving [3+2]-cycloaddition of azomethine ylides as the key step is described. The protocol provides a mild reaction condition, high yield of the products, high regioselectivity and operational simplicity to assemble complex structural entity in a single operation. The structure of the product was confirmed by spectroscopic and single crystal X-ray analysis. 相似文献
11.
Nasrin ZohrehAbdolali Alizadeh 《Tetrahedron》2011,67(25):4595-4600
A facile one-pot synthesis of N-phenyl-3,5-difunctionalized pyrazoles is described. The dialkyl 2-[(Z)-phenylhydrazono]succinate intermediate, which is prepared in situ from the mixture of phenylhydrazine and dialkyl acetylenedicarboxylate reacts with aroyl chloride or fumaryl chloride to afford the title compounds. Different types of compounds containing COCl functional group were used to investigate the scope and limitation of the reaction. Two -CO2R and -O2C groups at 3- and 5-position are potentially capable to convert to other functional groups. The reaction conditions are relatively mild and the yields are good. 相似文献
12.
Vinod Kumar 《Tetrahedron letters》2006,47(9):1457-1460
Treatment of aldoximes with N-tert-butyl-N-chlorocyanamide gave hydroximoyl chlorides in quantitative yields in less than a minute, which on dehydrohalogenation in the presence of triethylamine gave the corresponding nitrile oxides. The nitrile oxides underwent 1,3-dipolar addition to dipolarophiles and gave 2-isoxazolines in excellent yields under mild conditions. 相似文献
13.
Daniel C. Whitehead 《Tetrahedron letters》2009,50(6):656-8821
A simple and efficient methodology for the preparation of N-chlorinated hydantoins is presented. These versatile chlorenium sources were isolated in high yield after a simple recrystallization. Among the ten examples are the first chiral N-chlorohydantoins. 相似文献
14.
Polysubstituted pyridines are prepared in good yield and with total regiocontrol by the one-pot reaction of an alkynone, 1,3-dicarbonyl compound and ammonium acetate in alcoholic solvents. This new three-component heteroannulation reaction proceeds under mild conditions in the absence of an additional acid catalyst and has been used in the synthesis of dimethyl sulfomycinamate, the acidic methanolysis degradation product of the sulfomycin family of thiopeptide antibiotics. 相似文献
15.
16.
A simple one-pot synthesis of 3-cyano-4-benzopyrones directly from 2-hydroxyacetophenones using mild conditions is reported herein. 相似文献
17.
Benjamin Prek Jure Bezenšek Marta Kasunič Uroš Grošelj Jurij Svete Branko Stanovnik 《Tetrahedron》2014
Herein a simple one-pot metal-free synthesis of alkyl-, aryl-, heteroaryl- and alkoxycarbonyl substituted 1,3-bis(dimethylamino)benzene derivatives is described. The products were prepared from the corresponding methyl ketones or compounds with an α-methylene group in regard to the carbonyl group, using N,N-dimethylacetamide dimethyl acetal (DMADMA) as the reagent. 相似文献
18.
Deepak Kumar Barange 《Tetrahedron》2010,66(21):3754-2877
A convenient one-pot two-step procedure for the synthesis of hydroxyiminodihydrobenzofurans assisted by microwave irradiation in presence of silica gel is described herein. Cyclic 1,3-dicarbonyl compounds reacted smoothly with various nitroolefins to furnish hydroxyiminodihydrobenzofuran derivatives as the mixture of E and Z isomers. Clean reaction conditions, no work-up procedure, easy isolation and good yields of the products are the salient features of the methodology. 相似文献
19.
Elena A. Krasnokutskaya Assiya Zh. Kassanova Makpal T. EstaevaVictor D. Filimonov 《Tetrahedron letters》2014
The first method for the direct one-pot transformation of aminopyridines into pyridinyl trifluoromethanesulfonates is developed. The procedure involves diazotization of aminopyridines with sodium nitrite in a DMSO paste in the presence of trifluoromethanesulfonic acid. 相似文献
20.
Senbao Fan Tao Tong Liting Fang Jingyi Wu Erfei Li Honglan Kang Xin Lv Xiaoxia Wang 《Tetrahedron letters》2018,59(14):1409-1413
A convenient, inexpensive and effective approach to the synthesis of 2-o-cyanoaryl oxazole derivatives has been developed. Generally, the copper-mediated cyclization/coupling reactions afforded corresponding 2-cyanoaryl oxazoles and oxazolines in moderate to excellent yields. The functionalized oxazole derivatives may be useful in biological chemistry and medicinal science. Our investigation indicates that the formation of the oxazole ring might favor the CC bond forming process on the ortho-position of the aryl ring. And CuCN plays dual roles as a Lewis acid catalyst and a C-nucleophile in this transformation. 相似文献