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Letters in Organic Chemistry
ISSN: 1570-1786
Letters in Organic Chemistry
Volume 8, Number 3, March 2011
Contents
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Abstracts Pp. i-iv
Concise Synthesis of Bicyclic Aminals by Way of Catalytic Intramolecular C-H Amination and Evaluation of their Reactivity as Iminium Precursors Pp. 155-162
David Rodríguez-Lucena, Marie S.T. Morin and Philippe Compain
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Multicomponent Reactions Stereo- and Regioselective Three-Component Reaction in Water: Synthesis of Triazole Substituted β-Lactams Via Click Chemistry Pp. 163-169
Ming Lei, Wang-Ze Song, Zu-Jin Zhan, Sun-Liang Cui and Fang-Rui Zhong
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Ionic Liquid-Supported (ILS) (S)-Pyrrolidine Sulfonamide for Asymmetric Michael Addition Reactions of Aldehydes with Nitroolefins Pp. 170-175
Emmy M. Omar, Kritanjali Dhungana, Allan D. Headley and Mohd B.A. Rahman
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Facile Regioselective Synthesis of Benzofuran-Annulated Six-Membered Sulfur Heterocycles and the Occurrence of Thermal [1,3] Sigmatropic Rearrangement Pp. 176-179
Krishna C. Majumdar, Sanjay Nath, Buddhadeb Chattopadhyay and Krishanu Ray
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Synthesis and Cytotoxic Activities of 2-(4-(2-heterocycloethoxy)phenyl)-1,2,4 triazolo[1,5-a] Pyridines Pp. 180-183
Jun Chen and Guolin Zhang
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An Efficient Synthesis of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) by Ultrasonic Irradiation in Ionic Liquid Pp. 184-187
Hua Qian, Dabin Liu and Chunxu Lv
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Efficient and Convenient Synthesis of N3-(Acyloxymethyl)dihydro-pyrimidinones by a One-Pot Two-Step Method Pp. 188-192
Zheng-Jun Quan, Rong-Guo Ren, Yu-Xia Da, Zhang Zhang and Xi-Cun Wang
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Editor’s Choice
Synthesis of 6-Aminobenzopentathiepines by Reactions of 4-Nitro-benzodithiol-2-ones with NaHS Pp. 193-197
Tatyana M. Khomenko, Dina V. Korchagina, Nina I. Komarova, Konstantin P. Volcho and Nariman F. Salakhutdinov
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Efficient Synthesis of 5-Arylmethyl-5-phenylimidazolidine-2,4-dione (or 5-Arylmethyl-5-phenyl-2-thioxoimidazolidin-4-one) from Chalcone Oxides Under Ultrasound Irradiation Pp. 198-201
Ji-Tai Li, Xiao-Ya Xu and Ying Yin
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A New Catalytic Method for Eco-Friendly Synthesis of Quinoxalines by Zirconium (IV) Oxide Chloride Octahydrate Under Mild Conditions Pp. 202-209
Maasoumeh Jafarpour, Abdolreza Rezaeifard and Mahdieh Heidari
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A Facile and Efficient Approach to the Synthesis of Novel Chiral Molecular Tweezers Based on Deoxycholic Acid under Microwave Irradiation Pp. 210-215
Yu Chen, Zhi-Gang Zhao, Xing-Li Liu and Zhi-Chuan Shi
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Syntheses of Polydifluoroboryl Chelate Compounds Pp. 216-219
Jung-Hwan Kim and Young-Il Kim
[Abstract] [Supplementary Material] [Purchase
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Synthesis of Regio- and Stereoisomers of Highly Functionalized 1,2,3-Triazole substituted Cyclopentanes Pp. 220-228
Loránd Kiss, Enikő Forró and Ferenc Fülöp
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Abstracts
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Concise Synthesis of Bicyclic Aminals by Way of Catalytic Intramolecular C-H Amination and Evaluation of their Reactivity as Iminium Precursors
David Rodríguez-Lucena, Marie S.T. Morin and Philippe Compain
The concise synthesis of fused bicyclic aminals by way of intramolecular rhodium-catalyzed C-H amination is reported as well as the evaluation of their reactivity as iminium precursors. In contrast to the well-studied N,O-acetal systems, the aminals synthesized were found to be particularly stable under reaction conditions used for nucleophilic addition.
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Multicomponent Reactions Stereo- and Regioselective Three-Component Reaction in Water: Synthesis of Triazole Substituted β-Lactams Via Click Chemistry
Ming Lei, Wang-Ze Song, Zu-Jin Zhan, Sun-Liang Cui and Fang-Rui Zhong
Three-component reaction in water was used to prepare a series of triazole substituted trans-β-lactams from the corresponding trans-4-acetoxy-lactam, sodium azide, and alkynes via a Cu(I)-catalyzed click chemistry with base free. This highly stereo- and regioselective procedure is simple, clean and efficient.
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Ionic Liquid-Supported (ILS) (S)-Pyrrolidine Sulfonamide for Asymmetric Michael Addition Reactions of Aldehydes with Nitroolefins
Emmy M. Omar, Kritanjali Dhungana, Allan D. Headley and Mohd B.A. Rahman
A class of ionic liquid supported (ILS) (S)-pyrrolidine sulfonamide organocatalyst (1c), which was developed earlier in our lab, has been applied to a wider range of Michael addition reaction, involving various aryl-substituted nitroolefins and a series of aldehydes. Catalyst 1c catalyzes Michael additions in which only 2 equivalents of aldehydes to each equivalent of nitroolefin are required. With 10 mol% of ILS catalyst 1c loading, moderate to excellent yields (51-98%) with moderate enantioselectivities (28-83% ee) and high diastereoselectivities (syn/anti ratio up to 97/3) were obtained. Moreover, the catalyst 1c could be easily recycled and reused for at least 5 times with slightly reduced activities.
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Facile Regioselective Synthesis of Benzofuran-Annulated Six-Membered Sulfur Heterocycles and the Occurrence of Thermal [1,3] Sigmatropic Rearrangement
Krishna C. Majumdar, Sanjay Nath, Buddhadeb Chattopadhyay and Krishanu Ray
Thio-Claisen rearrangement of a number of 3-(4-aryloxybut-2–ynlthio)benzofurans has been achieved under very mild conditions to give 2H-benzo[b]thiopyrano[2,3-d]furans. Attempts at further thio-claisen rearrangement resulted in the occurrence of thermal [1s, 3a] sigmatropic shift.
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Synthesis and Cytotoxic Activities of 2-(4-(2-heterocycloethoxy)phenyl)-1,2,4 triazolo[1,5-a] Pyridines
Jun Chen and Guolin Zhang
Nine 2-(4-(2-heterocycloethoxy)phenyl)-1,2,4-triazolo[1,5-a] pyridines have been synthesized. The structures of all products were confirmed by 1H NMR and HRMS. The cytotoxic activities of these compounds were evaluated against human ovary cancer cell line (HO-8910) in vitro by MTT method. The preliminary results showed that compound 4e (IC50 0.11mM) and compound 4f (IC50 0.11mM) exhibited moderate activity against the cancer cell line when compared with Cisplatin.
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An Efficient Synthesis of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) by Ultrasonic Irradiation in Ionic Liquid
Hua Qian, Dabin Liu and Chunxu Lv
New process to synthesize HMX from 3,7-dinitro-1,3,5,7- tetraazabicyclo[3,3,1]nonane (DPT) using ultrasound in ionic liquid was developed. The reaction has been carried out in ultrasonic bath and the effect of various parameters such as presence and absence of ultrasound, volume and type of solvent, temperature, concentration of nitrating agent has been investigated with the aim of obtaining the optimum conditions for the synthesis of HMX. It was observed that yield was significantly enhanced from 42.3% up to 87.4% through the ultrasonically promoted nitrolysis of DPT to HMX at ambient condition.
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Efficient and Convenient Synthesis of N3-(Acyloxymethyl)dihydro-pyrimidinones by a One-Pot Two-Step Method
Zheng-Jun Quan, Rong-Guo Ren, Yu-Xia Da, Zhang Zhang and Xi-Cun Wang
3,4-Dihydropyrimidinones modified with N3-(acetoxymethyl) and (aroyloxymethyl) groups can be regioselectively obtained in good yields by reactions of 3,4-dihydropyrimidinones with paraformaldehyde and substituted benzoic acids/acetic acid, by a one-pot two-step strategy in the presence of chlorotrimethylsilane. The advantages of this method are the simple procedure, the high regioselectivity of the products, shorter reaction time and the mild reaction conditions. Additionally, this method directly uses acid as acylation reagents and needs not acid anhydride or acyl chloride.
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Synthesis of 6-Aminobenzopentathiepines by Reactions of 4-Nitro-benzodithiol-2-ones with NaHS
Tatyana M. Khomenko, Dina V. Korchagina, Nina I. Komarova, Konstantin P. Volcho and Nariman F. Salakhutdinov
The reactions of benzodithiol-2-ones containing a 4-nitro group with NaHS led to mixtures of 6-aminobenzopentathiepines and 4-nitrobenzotrithiols. The product ratio and yields depend on the substituent in the aromatic ring. Based on the yields of benzopentathiepines, the following series of substituent efficiency can be inferred: CF3 >> F, Cl > CN. Aminobenzopentathiepines are probably formed via the intermediate benzotrithiols; the transformation apparently starts with the reduction of the nitro group.
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Efficient Synthesis of 5-Arylmethyl-5-phenylimidazolidine-2,4-dione (or 5-Arylmethyl-5-phenyl-2-thioxoimidazolidin-4-one) from Chalcone Oxides Under Ultrasound Irradiation
Ji-Tai Li, Xiao-Ya Xu and Ying Yin
Synthesis of 5-arylmethyl-5-phenylimidazolidine-2,4-dione (or 5-arylmethyl-5-phenyl-2-thioxoimidazolidin-4-one) via the reaction of 3-aryl-2,3-epoxyl-1-phenyl-1-propanone and urea (or thiourea) was carried out in 57-98% yields at 50 °C in EtOH in the presence of KOH under ultrasound irradiation. The procedure has the advantages of mild conditions, short reaction time and high yield.
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A New Catalytic Method for Eco-Friendly Synthesis of Quinoxalines by Zirconium (IV) Oxide Chloride Octahydrate Under Mild Conditions
Maasoumeh Jafarpour, Abdolreza Rezaeifard and Mahdieh Heidari
An environmentally benign catalytic method for efficient synthesis of quinoxaline derivatives via the condensation reaction of 1,2-diamines and 1,2-dicarbonyl compounds using ZrOCl2.8H2O in EtOH as a standard green solvent under mild conditions has been developed. The reusability of the catalyst has been successfully examined without any noticeable loss of its catalytic activity.
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A Facile and Efficient Approach to the Synthesis of Novel Chiral Molecular Tweezers Based on Deoxycholic Acid under Microwave Irradiation
Yu Chen, Zhi-Gang Zhao, Xing-Li Liu and Zhi-Chuan Shi
A rapid, safe and efficient method for the synthesis of novel molecular tweezers with one chiral arm based on deoxycholic acid was reported. Ten new molecular tweezers have been synthesized in good yields. The structures of these new molecular tweezers were characterized by 1H NMR, IR, MS spectra and elemental analysis. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.
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Syntheses of Polydifluoroboryl Chelate Compounds
Jung-Hwan Kim and Young-Il Kim
A number of BF2-chleate compounds were developed based on 4,6-dichloropyrimidine. The electron withdrawing ability of the -BF2 group markedly enhances the reactivity of the chlorides within chloropyrimidine. Consequently the BF2-chelate compounds can be modified in a variety of ways by nucleophilic substitutions. The compounds prepared in this work consist of 4,6-dichloropyrimidine and BF2-chelate moieties separated by methylene chains of tunable lengths. Such a versatile series of compounds may provide an opportunity to study the intramolecular energy transfer processes with respect to the donor-acceptor distances. Also it is suggested that the present BF2-chelate compounds will be useful for developing various types of energy/electron transfer systems and fluorescent materials.
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Synthesis of Regio- and Stereoisomers of Highly Functionalized 1,2,3-Triazole substituted Cyclopentanes
Loránd Kiss, Enikő Forró and Ferenc Fülöp
Highly functionalized regio- and stereoisomers of 1,2,3-triazole-substituted cyclopentanes were prepared in six steps from either bicyclic β-lactam 7 or γ-lactam 23 by 1,3-dipolar cycloaddition of the azido cyclopentanol intermediates with acetylenes. The reactions of azido aminocyclopentanols with non-symmetric acetylenes resulted regioselectively in the corresponding 1,4-disubstitued triazole derivatives under both thermal and Cu(I)-catalysed conditions. These compounds can be regarded as highly functionalized 1,2,3-triazole-modified carbocyclic nucleoside analogues.
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