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- Volume 9, Issue 8, 2012
Letters in Organic Chemistry - Volume 9, Issue 8, 2012
Volume 9, Issue 8, 2012
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Convenient Synthesis of 1,4-Dihydroxy-2-(ω-Hydroxyalkoxy)Anthracene- 9,10-Diones and their Conjugation with D-Glucal
Authors: Sebastian Budniok and Krzysztof Z. WalczakPurpurin, 1,2,4-trihydroxyanthraquinone, was regioselectively alkylated under basic conditions using bromoalcohol of varying chain length. As a base, potassium carbonate, tetrabutylammonium hydroxide or 1,8- diazabicyclo[5.4.0]undec-7-ene (DBU) was used. The reaction of alkylation proceeded exclusively on the 2-hydroxyl group of the purpurin molecule. Addition of the obtained 2-(ω-hydroxyalkoxy)purpurins to prote Read More
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Synthesis, Structure and Attempted Polymerization of a Diepoxide Macrocycle
Authors: Paul Yarincik and Jeffrey H. GlansA novel diepoxide containing paracyclophane was synthesized by peracid oxidation of a known paracyclophane diene. The resulting diepoxide was characterized. It was investigated as a potential monomer for a cyclophane containing polyether by cationic ring opening polymerization. None of the standard catalyst systems for such a polymerization were successful in producing polymer.
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Synthesis of 1,3,6-Trioxygenated Prenylated Xanthone Derivatives as Potential Antitumor Agents
Authors: Chan K. Lim, Lai-Yeng Tho, Yang M. Lim, Syed A. A. Shah and Jean-Frederic F. WeberTo investigate the antitumor activities of xanthonic compounds, 10 prenylated xanthone derivatives 2-11 along with their key building block 1,3,6-trihydroxyxanthone 1 were evaluated for their potential cytotoxic activities against HeLa and MDA-MB-231 cancer cell lines. The synthesis afforded a series of prenylated derivatives with typical and new xanthone skeletons. Compounds 2, 3, 4 and 9 were reported for the first time to Read More
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Preparation of Reusable Dihydropyran-Functionalized Resins Cross- Linked with Tetrahydrofuran
Authors: Tomikazu Kawano, Seri Kurosawa, Kousuke Ikeuchi and Satoshi OgawaThe novel dihydropyranyl-functionalized resins, referred to as “JJ-DHP”, prepared from JandaJel-Cl resin, have been developed. We have also clarified that JJ-DHP has shown a good swelling property in common organic solvents and reusable ability in solid-phase organic synthesis.
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Preparation and Crystal Structure of a Supramolecular Bithiophene Network Complex with 1D Channel-Like Cavities
Authors: Naoki Shiota, Takafumi Kinuta, Tomohiro Sato, Takaya Kimoto and Yoshitane ImaiWe successfully prepared a novel supramolecular network complex having one-dimensional (1D) channel-like cavities by using 2-naphthylethylamine and 2,2'-bithiophene-5,5'-dicarboxylic acid. The EtOH molecules in this complex were trapped as guests in 1D channel-like cavities formed by the assembly of characteristic two-dimensional (2D) layered hydrogen- and ionic-bonded network structures.
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Synthesis of 2,5-Substituted Tetrahydrofurans by Pd(II)-Catalyzed Cyclization
Authors: Beata Olszewska, Boguslaw Kryczka and Anna ZawiszaThe Pd(II)-catalyzed cyclization of hydroxyl-substituted allylic alcohols quantitatively afforded a cis/trans mixture of 2,5-substituted tetrahydrofurans.
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Synthesis of the 3,4,5-Trimethoxy-2-(3,4-methylenedioxy-6-nitrophenyl) benzaldehyde for Divergent Preparation of Cytotoxic Biaryls
More LessThe regioselective synthesis of the 3,4,5-trimethoxy-2-(3,4-methylenedioxy-6-nitrophenyl)benzaldehyde as key intermediate for divergent preparation of cytotoxic biaryl lignans was achieved in three steps from commercially available starting materials. Reactivity of this synthon was illustrated by its conversion into the corresponding phenanthridine and bromomethylbenzene.
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Diastereoselective Organocatalytic Michael Addition of 2-Arylacetates Having an Electron-Withdrawing Group to Nitroalkenes
By Sung-Gon KimThe first efficient organocatalytic conjugate addition reaction of 2-arylacetates and 2-arylacetonitriles having an electron-withdrawing group to nitroalkenes has been achieved using a bifuctional amino thiourea catalyst. The reagents having NO2-, CO2Me-, and CN-functional groups on the aromatic ring can be used; the bifuctional catalyst 4i provided Michael adducts in the reaction of various nitroalkenes with broad general Read More
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The Synthesis of Allosamidin and Its Analogue Di-N-Acetyl-β-Chitobiosyl NAG-Thiazoline Using the Photosensitive o-Nitrobenzyl Ether Tether as Linker
Authors: Gangliang Huang and Fei ChengThe solid-phase synthesis of allosamidin and its analogue di-N-acetyl-β-chitobiosyl NAG-thiazoline were investigated. The synthesis was performed using polystyrene as support and o-nitrobenzyl ether tether as linker. The target allosamidin 1 and di-N-acetyl-β-chitobiosyl N-acetylglucosamine (NAG)-thiazoline 2 were efficiently obtained by iterative glycosylation reactions, catalytic hydrogenation, acetylation, deacetylation, and Read More
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22% Co/CeO2-ZrO2-catalyzed Synthesis of 1, 2, 3, 4-tetrahydro-2- pyrimidinones and -thiones
Authors: Hajar Biklarian, Farahnaz K. Behbahani and Zahra FakhroueianThree-component condensation reaction of an aldehyde with β-ketoester and urea or thiourea in acetonitrile to afford the dihydropyrimidinones and thions (DHPMs) in the presence of 22% Co/CeO2-ZrO2 nano fine particle as a novel, reusable and green catalyst is reported. Utilizing of 22% Co/CeO2-ZrO2 nano fine particle catalyst also offers a cleaner process in that it can be reused and will not bring additional pollutants int Read More
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Synthesis of Oxazolidinones, Dioxazolidinone and Polyoxazolidinone (A New Polyurethane) Via A Multi Component-Coupling of Aldehyde, Diamine Dihydrochloride, Terminal Alkyne and CO2
Authors: Djamila Teffahi, Smain Hocine and Chao-Jun LiIn the present paper, the coupling reaction of aldehyde, terminal alkyne, amine salt and CO2 was investigated. Copper iodide was found to be an efficient catalyst for the coupling reaction in ethyl acetate at 80 °C and under an atmospheric pressure of CO2. A diverse range of oxazolidinones was prepared by this method. Subsequently, a copper-catalyzed coupling of aldehyde, terminal alkyne, diamine salt and CO2 was develo Read More
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Novel De-Acylative Ring Opening of 3-Acetyl and 3-Bromo Acetyl Coumarins
More LessReaction of 3-acetyl and 3-bromoacetyl coumarins with hydrazine hydrate has resulted in the ring opening of the coumarin moiety. The reaction was attempted with a view to obtain some new pyridazinones and pyrazolones. The reaction did not proceed via the expected pathway instead led to the formation of salicyl azines, the structure of which has been confirmed by single crystal X-ray studies.
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Synthesis of Silica Bromide as Heterogeneous Reagent and its Application to Conversion of Alcohols to Alkyl Bromides
Authors: Farajollah Mohanazadeh, Mohammad A. Zolfigol, Alireza Sedrpoushan and Hojat VeisiSilica bromide as heterogeneous reagent is prepared from the reaction of silica gel with PBr3 as a nonhydroscopic, filterable, cheap, and stable yellowish powder that can be stored for months. The results show that the silica bromide is a suitable and efficient reagent for conversion of alcohols to alkyl bromides under mild conditions at room temperature. The easy availability of this reagent makes this simple procedure Read More
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Microwave Assisted Solvent-Free Synthesis of Novel Chenodeoxycholic Acid Thiosemicarbazone Derivatives and Studies on Antibacterial Activities
Authors: Zhi-Gang Zhao, Ping Yan, Xing-Li Liu and Zhi-Chuan ShiA rapid and efficient method for the synthesis of novel chenodeoxycholicacid acid thiosemicarbzones under solvent-free conditions using microwave has been developed. Their structures were elucidated by ESI-MS, IR, 1H NMR and elemental analysis. Nine novel compounds have been synthesized in good yields. Compared to the conventional method, microwave irradiation method, main advantages are short reaction ti Read More
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An Efficient Oxidation of 2,6-di-tert-Butylphenol to 3,3',5,5'-tetra-tert- Butyl-4,4'-Diphenoquinone Catalyzed by Lewis Acid System in the Presence of Molecular Oxygen
Authors: Hong-Ting Sheng, Hui Wang, Yan Feng, Jian-Hua Shi, Yong-Hua Jiao and Man-Zhou ZhuAn efficient and simple method for the preparation of 3,3',5,5'-tetra-tert-butyl-4,4'-diphenoquinone (TBDPQ) is reported using Lewis Acid as an effective catalyst in the presence of molecular oxygen from 2,6-di-tert-butylphenol (DBP). The present methodology offers several advantages, such as excellent yields, accessible and inexpensive catalysts, easy work-up and green conditions. The oxidation reaction was found to p Read More
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Volumes & issues
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Volume 22 (2025)
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Volume 21 (2024)
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Volume 20 (2023)
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Volume 19 (2022)
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Volume 18 (2021)
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Volume 17 (2020)
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Volume 16 (2019)
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Volume 15 (2018)
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Volume 14 (2017)
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Volume 13 (2016)
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Volume 12 (2015)
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Volume 11 (2014)
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Volume 10 (2013)
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Volume 9 (2012)
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Volume 8 (2011)
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Volume 7 (2010)
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Volume 6 (2009)
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Volume 5 (2008)
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Volume 4 (2007)
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Volume 3 (2006)
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Volume 2 (2005)
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Volume 1 (2004)
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