Letters in Organic Chemistry

ISSN: 1570-1786

Letters in Organic Chemistry
Volume 3, Number 11, November 2006

Diastereoselective Horner-Wadsworth-Emmons Reaction for the Synthesis of Tetrasubstituted Alkenes with an Axis of Chirality Pp. 798-801

Shigeki Sano, Shinobu Abe, Tomohiro Azetsu, Michiyasu Nakao, Motoo Shiro & Yoshimitsu Nagao An asymmetric Horner-Wadsworth-Emmons (HWE) reaction of σ-symmetric 4-methylcyclohexanone and a novel HWE reagent bearing O-benzylisomannnide was investigated. As a result, a tetrasubstituted alkene with an axis of chirality was obtained in > 99% de.

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Diastereoselective Addition of Organolithium to Ferrocene Carboxaldehyde Imines Derived from (R)- and (S)-1-Phenylethylamine: The Effect of External Additives Pp. 802-805

Hui-Qing Zhang, Zhi-Ming Zhou , & Min Fang High diastereoselectivity (93% de) was observed in the asymmetric addition of n-BuLi to ferrocenecarboxaldehyde imine 2b in the presence of the Lewis acids BF3•OEt2. And the lowest energy conformation of BF3-complexed imine 2b was obtained by a calculation using DMol3 software to explain the high stereoselectivity.

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Lower Rim Substituted p-tert-Butylcalix[4]arenes: Part XI. New Ester Derivatives of Calix[4]arene, Their Ionophoric Properties and X-ray Structure Studies Pp. 811-816

A convenient way to obtain carboxyl, phosphoryl or mixed calix based ester dendrimers is presented. New compounds can be applied as sensing materials in ion-selective membrane electrodes.

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A Novel Synthesis of 2-Substituted Indole Derivatives: A Palladium Catalyzed Cross-coupling Reaction of Enol Triflate Derived from N Methyl 2-Indolone with (Alkenyl)tributylstannane and Acetylene Pp. 817-819

Akimori Wada Masaki Shinmen, Jun ’ichi Uenishi & Masayoshi Ito A novel method for a synthesis of N-methyl-2-substituted indole was developed by a palladium catalyzed cross-coupling reaction of an enol triflate derived from the N-methyl-2-indolone with (alkenyl)tributylstannanes and acetylenes in good to excellent yields.

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Hexahydro-Pyrrolo[1’,2’,5’:3,4,5]Thiazolo[3,4-c]Oxazol-1-ones: New Chiral Tricyclic L-Cysteine and D-Penicillamine Derivatives Pp. 820-826

Teresa M.V.D. Pinho e Melo, Susana M.M. Lopes, António M. A. Rocha Gonsalves, Agnieszka Kaczor, Rui Fausto, José A. Paixão, Ana Matos Beja & Manuela Ramos Silva A one-pot synthesis of the new chiral hexahydropyrrolo[1',2',5':3,4,5]thiazolo[3,4-c]oxazol-1-one ring system from α-amino acids (L-cysteine and D-penicillamine) and succindialdehyde is reported.

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A New, Simple and Efficient Method for the Synthesis of 7-Aza bicyclo[2.2.1]heptane Derivatives: Formal Total Synthesis of Epibatidine Pp. 827-830

Elena Gómez-Sánchez & José Marco-Contelles The intramolecular base-mediated heterocyclization of alkyl N-(c-3,t-4 dibromocyclohex-1-yl)carbamates, or N-(c-3,t-4-dibromocyclohex-1-yl) 2,2,2-trifluoroacetamide is a convenient method for the synthesis of the 7-azabicyclo[2.2.1]heptane derivatives.

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Synthesis of Bispyridinium Compounds Bearing Propane Linker and Evaluation of their Reactivation Activity against Tabun- and Paraoxon-Inhibited Acetylcholinesterase Pp. 831-835

Kamil Musilek, Ondrej Holas, Jan Hambalek, Kamil Kuca, Daniel Jun, Vlastimil Dohnal & Martin Dolezal A series of bisquaternary reactivators of acetylcholinesterase (AChE) with propane connecting chain was synthesized and evaluated on tabun and paraoxon-inhibited AChE with promising results.

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S,S-Dimethyl Dithiocarbonate as a Valuable Starting Material for the Synthesis of 5-Substituted Oxazolidinones Under Solid-Liquid Phase Transfer Catalysis (SL-PTC) Conditions Pp. 836-841

Dario Landini, Matteo Salsa, Gianni Carvoli & Ilir Pecnikaj 5-substituted oxazolidinones were prepared in good to excellent yields by reaction of 1,2-amino alcohols with S,S-dimethyldithiocarbonate under SL-PTC conditions.

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An Efficient Synthesis of Benzils from Hydrobenzoins by CrO3-NH4Cl under Ultrasound Irradiation Pp. 842-844

Ji-Tai Li & Xue-Li Sun The oxidation of hydrobenzions to the corresponding benzils was carried out in CH2Cl2 by CrO3-NH4Cl in excellent yield at room temperature under ultrasound irradiation.

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Synthesis of Oxepin- and Oxocin- Annulated Pyrimidine Derivatives by Claisen Rearrangement and Ring Closing Metathesis/Ring Closing Enyne Metathesis Pp. 845-847

Krishna C. Majumdar, Pradip K. Maji, Habibur Rahaman & Brindaban Roy A practical synthesis of oxepin and oxocin-annulated pyrimidine derivatives is described by the combination of Claisen rearrangement and metathesis reaction.

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HClO4-SiO2 Catalyzed Multicomponent Reactions for the Synthesis of Privileged Heterocyclic Structures Pp. 848-853

Pintu Kumar Mandal & Anup Kumar Misra A series of multicomponent reactions have been carried out using HClO4-SiO2 as a versatile catalyst. In all cases, the reaction conditions are very simple and high yielding.

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Electrochemical Synthesis of Selenocarbonates Pp. 854-856

Alessandra La Groia, Marta Feroci, Achille Inesi & Leucio Rossi Electrochemical reduction of diselenides (1) allows the formation of selenide anions which react with different chloroformates (2) yielding the corresponding selenocarbonates (3) in moderate to very high yields.

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Convenient Synthesis of α-Amino Acid-Derived Cyclic Amides for Use as Building Blocks for Protease Inhibitors Pp. 857-860

Maxim E. Sergeev & Tatiana L. Voyushina An efficient and straightforward approach towards the synthesis of alpha amino acid-derived cyclic amides was developed. A series of cyclic amides of various natural amino acids were obtained in excellent yields under mild conditions. The obtained compounds could be efficiently used as ligands for affinity chromatography of enzymes.

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A Concise Approach to the Dibenzo[1,4]Dioxocin Structure Pp. 861-864

Anna Zawisza, Loïc Toupet & Denis Sinou The palladium(0)-catalyzed heteroannulation of 2,2'-diphenol and the biscarbonate of butenediol afforded quantitatively rac-(SA,6 R)-6-vinyl-6,7 dihydrodibenzo[e,g][1,4]dioxocine. The use of chiral ligands gave this unique stereoisomer with ee up to 30%.

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Synthesis of First Tetrathiafulvalene-Carbohydrate Derivatives Pp. 865-867

Angelica M. Heinrich, Shahnaz Perveen, Gerardo C. Janairo, Gernot Bruchelt, Khalid Mohammed Khan, Syed Tasadaque Ali Shah, Ghulam Murtaza Maharvi and Wolfgang Voelter A convenient and novel method for the synthesis of tetrathiafulvalene carbohydrate (TTF) derivatives from anhydro triflyl-, iodo- and bromo sugars is described.

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An Expeditious Approach to Knoevenagel Condensation of Meldrum’s Acid on Neutral Alumina Using Microwave Irradiation Pp. 868-871

Manas Chakrabarty, Ratna Mukherjee, Manju Chakrabarty, Shiho Arima & Yoshihiro Harigaya Application of microwave irradiation to a mixture of Meldrum’s acid and aryl aldehydes, both adsorbed on neutral alumina, furnished efficiently the corresponding Knoevenagel condensation products remarkably fast.

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Selective Deprotection of Bisulfite Addition Products by FeCl3•6H2O and Fe(NO3)3•9H2O Supported on Silica Gel Under Solvent-Free Conditions Pp. 872-876

Iraj Mohammadpoor-Baltork , Mohammad Mehdi Khodaei , & Hamideh Ahankar An efficient and selective method for deprotection of bisulfite addition products in the presence of catalytic amounts of FeCl3•6H2O and Fe(NO3)3•9H2O supported on silica gel under solvent-free conditions is reported.