共查询到20条相似文献,搜索用时 15 毫秒
1.
Alexander S. Tikhomirov Andrey E. Shchekotikhin Yuri N. Luzikov Alexander M. Korolev Maria N. Preobrazhenskaya 《Tetrahedron》2014
A new facile route to the synthesis of 4,11-dimethoxyanthra[2,3-b]furan-5,10-dione and its novel 2-substituted derivatives was proposed. The developed scheme was based on a Pd-catalyzed cross-coupling/heterocyclization domino reaction of 3-bromo-2-hydroxy-4,11-dimethoxyanthraquinone with terminal alkynes. 相似文献
2.
An efficient, copper-free Sonogashira coupling reaction of 1-chloroisoquinolines and terminal alkynes, catalyzed by Pd(OAc)2/Ruphos, in the presence of Et3N and tetrahydrofuran leads to the formation of 1-alkynyl-3-substituted isoquinolines in good yields. 相似文献
3.
M. S. Shvartsberg E. A. Kolodina N. I. Lebedeva L. G. Fedenok 《Russian Chemical Bulletin》2012,61(3):582-588
The Pd-catalyzed reaction between 3-acetylamino-2-bromo-1,4-naphthoquinones and CuI acetylides prepared in situ gave 3-acetylamino-2-alkynyl-1,4-naphthoquinones, which were transformed into benz[f]indole-4,9-dione and benzo[g]quinoline-5,10-dione derivatives. 相似文献
4.
Jan Jacobs 《Tetrahedron》2008,64(22):4985-4992
The synthesis of N-substituted 1,2-dihydrobenz[g]isoquinoline-5,10-diones was envisaged as part of our research on structural modifications of pentalongin, the active principle of Pentas longiflora Oliv. Therefore, a synthesis of the 2-aza analogues of this natural pyranonaphthoquinone with an acid-mediated intramolecular cyclization of different N-protected 2-(((2,2-dimethoxyethyl)amino)methyl)-1,4-naphthoquinones in the key step was conducted. The synthesized 1,2-dihydrobenz[g]isoquinoline-5,10-diones represent a new class of compounds, which has been undescribed in organic chemistry. 相似文献
5.
Subhasis De 《Tetrahedron》2007,63(45):10939-10948
2-BF3-substituted 1,3-butadienes with potassium and tetrabutyl ammonium counterions have been prepared in gram quantities from chloroprene via a simple synthetic procedure. The potassium salt of this new main group element substituted diene has been characterized by 1H, 13C, 11B, and 19F NMR and the tetra n-butyl ammonium salt was also characterized by X-ray crystallography. Diels-Alder reactions of these dienes with dienophiles such as ethyl acrylate, methyl vinyl ketone, and N-phenylmaleimide are reported as well as subsequent Pd-catalyzed cross-coupling reactions of those Diels-Alder adducts. 4-Phenyl-2-BF3-substituted 1,3-diene was prepared by magnesium-halogen exchange from the corresponding 2-bromo and iodo dienes. The 4-phenyl-2-bromo-1,3-butadiene was also characterized by X-ray crystallography. 4-Phenyl-2-BF3-1,3-butadiene was used in Diels-Alder/cross-coupling reactions and the product of a Diels-Alder reaction with N-phenylmaleimide followed by cross-coupling with 4-bromo-benzonitrile was also characterized by X-ray crystallography. 相似文献
6.
Zhiyong Wang 《Tetrahedron》2008,64(8):1736-1742
An efficient and novel route for the synthesis of 1H-indol-2-yl-(4-aryl)-quinolin-2(1H)-one 1 via palladium-catalyzed site-selective cross-coupling reaction and cyclization process was described. Reaction of 3-bromo-4-trifloxy-quinolin-2(1H)-one 3 with arylboronic acid catalyzed by PdCl2(PPh3)2 afforded 3-bromo-4-aryl-quinolin-2(1H)-one 4, which then reacted with 2-ethynylaniline 5 via Pd-catalyzed Sonogashira coupling and CuI-mediated cyclization leading to the desired 1H-indol-2-yl-(4-aryl)-quinolin-2(1H)-one 1 in good yields. 相似文献
7.
Mohosin Layek A.V. Dhanunjaya Rao Dipak Kalita Aminul Islam Manojit Pal 《Tetrahedron letters》2009,50(34):4878-238
We report copper-catalyzed intramolecular cyclization of 8-alkynyl-1,2,3,4-tetrahydroquinolines, obtained via a Pd/C-mediated Sonogashira coupling in water, to afford 2-substituted 5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinolines. Further functionalization of the compounds synthesized was carried out under Heck, Sonogashira, and Suzuki reaction conditions. 相似文献
8.
Yuan-Yuan Hu 《Tetrahedron》2010,66(1):80-6894
2-Azido-3-(2-iodophenyl)acrylates react with terminal alkynes in the presence of a copper(II) catalyst without ligands to give a wide range of [1,2,3]triazolo[5,1-a]isoquinolines in good yields. These compounds favor expulsion of N2 in refluxed acetic acid to form 1,3-disubstituted isoquinolines. The procedure is simple, economical, and efficient. 相似文献
9.
A series of 3-(N-substituted)-aminoquinolin-2(1H)-ones have been synthesized by the palladium-catalyzed C-N coupling reaction starting from 3-bromoquinolin-2-(1H)-ones. Various nucleophiles including amines, amides, sulfonamides, carbamates and ureas have been used successfully. In all the cases, the reactions take place rapidly in 1,4-dioxane and proceed in good to excellent yield using palladium acetate as a catalyst, Xantphos as a ligand and Cs2CO3 as a base. 相似文献
10.
Sirisilla Raju Venkateswara Rao Batchu R. Vasu Dev J. Moses Babu P. Rajender Kumar Pazhanimuthu Annamalai 《Tetrahedron》2006,62(41):9554-9570
We herein report a highly convenient protocol for rapid construction of α-pyrone fused with thiophene. This includes one-pot and regioselective synthesis of 4,5-disubstituted and 5-substituted thieno[2,3-c]pyran-7-ones, 6,7-disubstituted and 6-substituted thieno[3,2-c]pyran-4-ones. The synthesis of thieno[2,3-c]pyran-7-ones involves palladium mediated cross coupling of 3-iodothiophene-2-carboxylic acid with terminal alkynes in a simple synthetic operation. The coupling-cyclization reaction was initially studied in the presence of Pd(PPh3)2Cl2 and CuI in a variety of solvents. 5-Substituted 4-alkynylthieno[2,3-c]pyran-7-ones were isolated in good yields when the reaction was performed in DMF. Similarly, 6-substituted 7-alkynylthieno[3,2-c]pyran-4-ones were synthesized via palladium-catalyzed cross coupling of 2-bromothiophene-3-carboxylic acid with terminal alkynes. A tandem C-C bond forming reaction in the presence of palladium catalyst rationalizes the formation of coupled product in this apparently three-component reaction. The cyclization step of this coupling-cyclization-coupling process occurs in a regioselective fashion to furnish products containing six-membered ring only. This sequential C-C bond forming reaction however, can be restricted to the formation of single C-C bond by using 10% Pd/C-Et3N-CuI-PPh3 as catalyst system in the cross coupling reaction. 5-Substituted thieno[2,3-c]pyran-7-ones were obtained in good yields when the coupling reaction was performed under this condition. Some of the compounds synthesized were tested in vitro for their anticancer activities. 相似文献
11.
A series of new para-substituted (E)-(N)-styrylcarbazoles, i.e., eight (E)-9-[2-(aryl)ethenyl]-9H-carbazoles (5-12) and 1,4-bis[(E)-2-(9H-carbazol-9-yl)vinyl]benzene (13), have been synthesized in high yield and stereoselectively by a sequential silylative coupling-Hiyama coupling reaction, i.e., coupling of commercially available 9-vinylcarbazole with vinyltriethoxysilane or divinyltetramethyldisiloxane in the presence of [RuHCl(CO)(PCy3)2] (I), followed by Pd (II) catalyzed cross-coupling with para-substituted iodobenzenes.The tandem procedure has facilitated the synthesis of 13. X-ray structures of the intermediate silylvinylcarbazole (4), as well as products 12 and 13 have been obtained. 相似文献
12.
Adriane Sperança 《Tetrahedron letters》2010,51(1):36-391
3-Iodo-4-chalcogen-2H-benzopyran derivatives underwent a direct Sonogashira cross-coupling reaction with several terminal alkynes in the presence of a catalytic amount of Pd(PPh3)2Cl2 with CuI as a co-catalyst, using Et3N as base and solvent. This cross-coupling reaction proceeded cleanly under mild conditions and was performed with propargylic alcohols, propargylic ethers, as well as alkyl and aryl alkynes, furnishing the correspondent 3-alkynyl-4-chalcogen-2H-benzopyrans in good yields. 相似文献
13.
A new and efficient strategy for the synthesis of 3-substituted 1-hydroxybenz[g]isoquinoline-5,10-diones by reaction of 2-methoxycarbonyl-1,4-naphthoquinone with different pyridinium salts under Kröhnke conditions is disclosed. This one-step reaction was found to be dependent on the substitution pattern of the aromatic nucleus in the pyridinium salts. 相似文献
14.
The synthesis of 1,2,3,4-tetrahydrobenz[g]isoquinoline-5,10-dione hydrochlorides is reported starting from 1,4-dihydrobenz[g]isoquinoline-3(2H)-ones or ethyl (3-aminomethyl-1,4-dimethoxynaphth-2-yl)acetates. A third strategy relies on the synthesis of the title compounds via an N-protected 2-(3-bromomethyl-1,4-dimethoxynaphth-2-yl)ethylamine. The synthesized 1,2,3,4-tetrahydro-benz[g]isoquinoline-5,10-diones are a new class of quinones, which have not been reported yet. 相似文献
15.
Leonid G. Voskressensky Anna V. Listratova Alexander V. Bolshov Oksana V. Bizhko Tatiana N. Borisova Alexey V. Varlamov 《Tetrahedron letters》2010,51(5):840-9617
Reaction of 5-bromo-2-methyl-8-nitro-1,2,3,4-tetrahydroisoquinoline with activated alkynes affords stable tetrahydropyrrolo[2,1-a]isoquinolin-4-ium ylides. Further reactions of ylide 2 gives access to substituted dihydropyrrolo[2,1-a]isoquinolines in good yields. 相似文献
16.
Related to our research on structural modifications of pentalongin, the active principle of the medicinal plant Pentas longiflora Oliv., a new synthesis of N-protected 1,2-dihydrobenz[g]isoquinoline-5,10-diones and their 4-methyl derivatives, which represent a new class of compounds, is reported. In both cases, the benz[g]isoquinoline skeleton was constructed by an intramolecular Heck reaction of N-protected 2-((allylamino)methyl)-3-bromo-1,4-dimethoxynaphthalenes and N-protected 2-((allylamino)methyl)-3-bromo-1,4-naphthoquinones, respectively. 相似文献
17.
De-Yang Zhang Chang-Bin Yu Min-Can Wang Kai Gao Yong-Gui Zhou 《Tetrahedron letters》2012,53(20):2556-2559
A new electronically deficient atropisomeric diphosphine ligand (S)-CF3O-BiPhep was synthesized from 1-bromo-3-(trifluoromethoxy)benzene in high yield. The key steps included oxidative coupling with anhydrous ferric chloride and optical resolution by (+)-DMTA. The ligand afforded high performance for Ir-catalyzed asymmetric hydrogenation of quinolines with ee up to 92% and TON up to 25,000. It was also successfully applied to the Pd-catalyzed asymmetric hydrogenation of simple indoles with ee up to 87% and Rh-catalyzed asymmetric 1,4-addition of phenylboronic acid to 2-cyclohexenone with 97% ee. 相似文献
18.
Goutam Kumar Jana 《Tetrahedron letters》2010,51(15):1994-6169
A concise route to iboga-analogues has been developed. Important steps include a Pd-catalyzed Sonogashira coupling of Boc-2-idodaniline with terminal alkynes and the formation of 2-substituted indoles in the presence of tetrabutylammonium fluoride to give the key intermediate, dehydroisoquinuclidine-containing indole. The final step cyclization between indole-3-position and dehydroisoquinuclidine ring was achieved using Pd(II)-Ag(I) mixed metal-mediated cyclization method. Both exo- and endo-substitution with -CO2Me at C19 have been reported. 相似文献
19.
Ken Takaki Sadayuki Koizumi Yuta Yamamoto Kimihiro Komeyama 《Tetrahedron letters》2006,47(41):7335-7337
Intermolecular hydroamination of alkynes catalyzed by Ti(NMe2)4 was much improved with N-heterocyclic carbenes and LiN(SiMe3)2, by which high Markovnikov selectivity was attained for the coupling of nearly all alkynes and amines. 相似文献
20.
Mark S. Shvartsberg Ekaterina A. Kolodina Nadezhda I. Lebedeva Lidiya G. Fedenok 《Tetrahedron letters》2009,50(49):6769-6771
A synthetic route to benz[f]indole-4,9-diones from 1,4-naphthoquinone is described. Effective methods for cross-coupling of 3-acetylamino-2-bromo-1,4-naphthoquinone with terminal acetylenes and cyclization of the resulting 3-acetylamino-2-alkynyl-1,4-naphthoquinones are developed. 相似文献