HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Special Issue
Akira Suzuki's Special Issues,Vol. 80, No. 2, 2010
Published online: 21st December, 2009
■ Divergent Synthesis of 2,3,5-Substituted Thiophenes by C-H Activation/Borylation/Suzuki Coupling
Venkata A. Kallepalli, Luis Sánchez, Hao Li, Nathan J. Gesmundo, Clarissa L. Turton, Robert E. Maleczka, Jr.,* and Milton R. Smith, III*
*Department of Chemistry, Michigan State University, East Lansing, MI 48824-1322, U.S.A.
Abstract
C–H activation/borylation has been married with Suzuki coupling to prepare DuP 697 (1) and analogs that would be otherwise difficult to obtain via the traditional synthetic route to 1.
Published online: 4th September, 2009
■ Stereoselective Preparation of Oxygenated Heterocycles Using Stereocontrolled Tandem Double-Allylation of Carbonyl Compounds with a Boron-Silicon Reagent
Umakanthan Sivasubramaniam and Dennis G. Hall*
*Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
Abstract
A one-pot three-component reaction between carbonyl double-allylation reagent 1 and aldehydes was optimized to provide a high diastereoselectivity in the formation of all-cis trisubstituted tetrahydrofurans. A similar procedure applied to dicarbonyl substrates provided an oxabicyclic compound embedding an 8-membered medium ring.
Published online: 15th September, 2009
■ Tetrahydroquinazoline Derivatives by Aza Diels-Alder Reaction
Giuseppe Cremonesi, Piero Dalla Croce,* Maddalena Gallanti, and Concetta La Rosa
*Department of Organic and Industrial Chemistry, Faculty of Pharmacy, University of Milano, Via Venezian 21, I-20133 Milano, Italy
Abstract
The reaction of N-(2-Chloromethylphenyl)benzenesulfonamides (1) with N-benzylideneamines (2) gives 1,2,3,4-tetrahydroquinazoline derivatives (3) via the highly reactive o-azaxylylene intermediates. The structure of (3) is fully assigned on the basis of analytical and spectroscopic data. The chemical behaviour of (3) has been studied.
Published online: 9th September, 2009
■ A Short Access to Chiral Non-Racemic Oxa- and Azaheterocycles by Cross-Metathesis and Pd-Catalyzed Cyclization Sequence
Jun'ichi Uenishi* and Yogesh S. Vikhe
*Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan
Abstract
A concise synthesis of chiral non-racemic 2-(3-benzoyloxyprop-1-enyl)tetrahydrofuran (5a), tetrahydropyran (5b), and piperidine (8) is described. Cross-metathesis of optically pure (S)-1-O-benzoyl-3-butene-1,2-diol (2) with protected 4-pentenol, 5-hexenol, and 5-hexenylamine gave the corresponding allyl alcohols (3a), (3b), and (7) in one step, respectively. PdCl2(MeCN)2 catalyzed cyclization of 4a, 4b, and 7 afforded 5a, 5b, and 8 in excellent yields with high enantiomeric purity.
Published online: 24th September, 2009
■ Gaudichaudysolin A, a New Limonoid from the Bark of Dysoxylum gaudichaudianum
Yuta Nagakura, Reiko Yamanaka, Yusuke Hirasawa, Takahiro Hosoya, Abdul Rahman, Idha Kusumawati, Noor Cholies Zaini, and Hiroshi Morita*
*Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
Abstract
A new limonoid, gaudichaudysolin A (1) was isolated from the bark of Dysoxylum gaudichaudianum (Meliaceae) and the structure was elucidated by spectroscopic analysis.
Published online: 15th September, 2009
■ Oxidative Dimerization of 4-Methoxynaphthylamines in the Presence of Semiconductors
Tetsuya Takeya,* Yosuke Takahashi, Iwao Okamoto, and Osamu Tamura*
*Showa Pharmaceutical University, 3-3165, Higashi-tamagawagakuen, Machida, Tokyo 194-8543, Japan
Abstract
Three types of 4-methoxynaphthylamines 4a-c were oxidized by treatment with metal oxides under molecular oxygen (O2). 4-Methoxy-1-naphthylamine 4a and 4,6-dimethoxy-1-naphthylamine 4b, on treatment with TiO2 under O2, gave mainly 2-amino-1,4-naphthoquinone derivatives 5a and 5b, respectively whereas 4,8-dimethoxy-1-naphthylamine 4c afforded an unique carbazole 6c as the major product.
Published online: 20th November, 2009
■ The Mukaiyama Aldol and Mukaiyama–Michael Reactions Promoted by Commercially Available Molecular Sieves
Masahiro Anada, Takuya Washio, Yudai Watanabe, and Shunichi Hashimoto*
*Laboratory of Synthetic and Industrial Chemistry, Graduate School of Life Science, Division of Life Science, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan
Abstract
The Mukaiyama aldol reaction of silyl ketene acetals with aldehydes has been effected by using commercially available 4Å molecular sieves (4Å MS) as a promoter. Various silyl ketene acetals and silyl enol ethers have been shown to be effective nucleophiles for this reaction. For the first time, it has been found that 4Å MS can promote the Mukaiyama–Michael addition reactions of silyl ketene acetals to α,β-enones.