共查询到20条相似文献,搜索用时 7 毫秒
1.
Diptesh Sil 《Tetrahedron letters》2005,46(30):5013-5015
A one-pot efficient synthesis of highly functionalized 5,6-dihydronaphthalenes has been delineated through carbanion-induced ring transformation of 2H-pyran-2-ones by 2-cyclohexenone. 相似文献
2.
A mild and efficient method for the synthesis of 1H-chromeno[2,3-d]pyrimidine-5-carboxamide derivatives via a one-pot, three-component reaction of an isocyanide, barbituric acid, and a salicylaldehyde in the presence of acetic acid in ethanol/water mixture at 75 °C is reported. This high atom economy reaction led to the construction of one benzopyran ring, and one amide group in a single synthetic step. 相似文献
3.
Liang-Yeu Chen Sie-Rong Li Po-Yuan Chen Chia-Ling Hsu Tzu-Pin Wang 《Tetrahedron letters》2009,50(41):5748-9297
Utilization of a novel carbanion-olefin intramolecular 6-endo-trig cyclization reaction to provide 2-aroyl-3,4-dihydro-2H-benzopyrans is described. Through a sequence of a Wittig reaction, O-alkylation, and carbanion-olefin intramolecular cyclization, salicylaldehydes were converted into a series of new 2-aroyl-3,4-dihydro-2H-benzopyrans in two steps or in one-pot reaction. 相似文献
4.
Ramendra Pratap 《Tetrahedron》2006,62(34):8158-8163
Substituent-controlled regioselective synthesis of highly functionalized 1,2-teraryls 3a-k has been achieved through ring transformation of 6-aryl-4-(pyrrolidin-1-yl/piperidin-1-yl)-2H-pyran-2-one-3-carbonitriles 1a-g by aryl acetones 2a-c in the presence of powdered KOH in DMF in very good yield. Under similar reaction conditions, 6-aryl-4-methylsulfanyl-2H-pyran-2-ones 5a-f afforded 1,7-diaryl-2-methyl-4H,5H-pyrano[3,4-c]pyran-4,5-diones 6a-j as major products and 3,4-diaryl-2-methyl-6-methylsulfanylbenzonitriles as minor constituents 7a-j. 相似文献
5.
Ramendra Pratap 《Tetrahedron letters》2005,46(30):5025-5027
The one-pot substituent-directed regioselective synthesis of 1,7-diaryl-2-methyl-4H,5H-pyrano[3,4-c]pyran-4,5-diones 3 as the major and 3,4-diaryl-2-methyl-6-methylsulfanylbenzonitriles 4 as the minor products has been delineated through ring transformation of suitably functionalized 2H-pyran-2-ones 1 with aryl acetones 2. Under similar reaction conditions, 6-aryl-4-sec-amino-2H-pyran-2-ones 5 led, regioselectively, to 3,4-diaryl-2-methyl-6-sec-aminobenzonitriles 6. 相似文献
6.
Ahmad Shaabani Ebrahim Soleimani Ralf-Dieter Hoffmann Rainer Pöttgen 《Tetrahedron letters》2006,47(31):5493-5496
A three-component condensation reaction between an isocyanide, an electron-deficient acetylenic ester and (ethoxycarbonylmethyl)triphenylphosphonium bromide efficiently provides fully substituted N-alkyl-2-triphenylphosphoranylidene glutarimides in a one-pot reaction without any activation or modification. 相似文献
7.
A novel, one-pot, three-component synthesis of 4H-pyrido[1,2-a]pyrimidines is described. The reactive 1:1 zwitterionic intermediate, formed by the addition of isocyanides to dialkyl acetylenedicarboxylates, was trapped by N-(2-pyridyl)amides to produce the title compounds under mild reaction conditions in good yields. 相似文献
8.
Highly functionalized (E)-stilbenes 3a-m and 4-aryl-6-styryl-pyran-2-ylidineacetonitriles 4a-b have been prepared and delineated through the ring transformation of 6-aryl-3,4-disubstituted-2H-pyran-2-ones 1 with commercially available (E/Z)-4-phenyl-3-buten-2-one 2 without the use of any catalyst. 相似文献
9.
A novel synthesis of highly functionalized alkylsulfanylmethyl arenes 8a-m through the ring transformation of 6-aryl-4-methyl/ethylsulfanyl-2H-pyran-2-one-3-carbonitriles 1a-j, by reaction with methyl vinyl ketone 2, is delineated and illustrated. To ascertain the course of reaction, 3-arylsulfanylmethyl-2-methyl-6-methylsulfanyl-4-phenylbenzonitriles 8k-m were also prepared from the reaction of 1 with 4-arylsulfanyl-butan-2-ones 7c,d. 相似文献
10.
Issa Yavari Farough Nasiri Loghman Moradi Hoorieh Djahaniani 《Tetrahedron letters》2004,45(38):7099-7101
Reaction of tert-butyl isocyanide with electron-deficient acetylenic esters in the presence of N1-[(Z)-1-benzoyl-3-oxo-3-phenyl-1-propenyl]-2-(2-furyl)-2-oxoacetamide leads to dialkyl 5-tert-butylamino-[2,2′]bifuranyl-3,4-dicarboxylates in moderate yields. 相似文献
11.
Diptesh Sil 《Tetrahedron letters》2004,45(44):8195-8197
An efficient synthesis of ethyl 7-aryl-2-methyl-4H,5H-pyrano[3,4-c]pyran-4,5-dione-1-carboxylate 5, and ethyl 6-aryl-3-cyano-2H-pyran-2-one-4-acetate 6 has been delineated by reaction of suitably functionalized 2H-pyran-2-ones 1 with ethyl acetoacetate 2. 相似文献
12.
Sixteen 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones have been synthesized by microwave-assisted Biginelli reactions in a short and concise manner employing ZnI2 as a catalyst under solvent-free conditions. All products were identified by IR, NMR, elemental analysis and HRMS. The advantages of this novel protocol include the excellent yield, operational simplicity, short time and the avoidance of the use of organic solvents and expensive catalysts. 相似文献
13.
Srinivasa Rao Kolla 《Tetrahedron》2010,66(46):8938-8944
This paper describes a simple and efficient one-pot synthetic approach for the preparation of biologically interesting 3,4-dihydroquinoxalin-2-amine derivatives using EDTA-catalyzed three-component reactions of o-phenylenediamines, carbonyl compounds, and isocyanides in an aqueous medium. This method is of great value because of its environmentally benign character, high yields, and ease of handling. 相似文献
14.
Ferric perchlorate catalyzes the three-component condensation reaction of o-phenylenediamine, aromatic aldehydes, and cyclohexyl isocyanide to afford the corresponding N-cyclohexyl-3-aryl-quinoxaline-2-amines in good yields. 相似文献
15.
Jabbar Khalafy Nasser EtivandShadi Dilmaghani Mahnaz EzzatiAhmad Poursattar Marjani 《Tetrahedron letters》2014
A simple and convenient synthesis of 2-aryl-3-hydroxy-6,7-dihydro-1H-indol-4(5H)-ones is achieved in high yields via the one-pot, three-component reaction of arylglyoxals, 1,3-cyclohexanedione, and ammonium acetate in water under reflux conditions. 相似文献
16.
A new approach to caerulomycins A and E via a 6-methyl-2-(2-pyridyl)-4H-pyran-4-one is described. The pyranone precursor is prepared by Claisen condensation of acetylacetone enol ether with ethyl picolinate. 相似文献
17.
L. Chandrasekhara Rao H.M. Meshram N. Satish Kumar N. Nageswara Rao N. Jagadeesh Babu 《Tetrahedron letters》2014
A convenient and efficient method is described for the synthesis of alkoxy substituted 2H-chromens by l-proline catalyzed reaction of salicylaldehydes with diketone in alcohol. The method is applicable for various substituted salicylaldehydes and aliphatic as well as benzylic alcohols. 相似文献
18.
Ayyakannu Arumugam Napoleon Fazlur-Rahman Nawaz Khan Euh Duck Jeong Eun Hyuk Chung 《Tetrahedron letters》2014
An efficient, three-component domino reaction of dimedone 1, aromatic aldehydes (2a–o), and 1,3-cyclohexanedione 1a in the regio-selective synthesis of 3,3-dimethyl-9-phenyl-2H-xanthene-1,8(5H,9H)-diones (3a–o) is reported. The desired product, 3 is efficiently promoted by ascorbic acid as an organo catalyst. 相似文献
19.
20.
Ahmad Shaabani Mozhdeh Seyyedhamzeh Ali Maleki Fatemeh Hajishaabanha 《Tetrahedron》2010,66(23):4040-4167
5-Carboxamide substituted 3,4-dihydropyrimidine-2(1H)one derivatives were synthesized in a simple and efficient method from the one-pot four-component reactions of an aliphatic or aromatic amine, diketene, an aromatic aldehyde and urea or thiourea in the presence of p-toluenesulfonic acid as a catalyst under mild reaction conditions at ambient temperature. 相似文献