HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Regular Issue
Vol. 75, No. 10, 2008
Published online: 15th May, 2008
■ Recent Trends in the Chemistry of Molecular Complexes of Heteroaromatic N-Oxides
Alexander V. Ryzhakov* and Ludmila L. Rodina
*Northern Water Problems Institute, Russian Academy of Sciences, 50 Alexander Nevsky Av., 185030 Petrozavodsk, Russia
Abstract
Literature review on molecular complexes of aromatic N-oxides with various electron acceptors published in the last decade is presented. Structure, chemistry, and new preparation methods of these complexes are discussed.
Published online: 28th March, 2008
■ Chemistry and Applications of 4,5-Diazafluorenes
Katsuhiko Ono* and Katsuhiro Saito
*Department of Life and Material Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
Abstract
The synthesis, molecular structures, reactions, and properties of 4,5-diazafluorene derivatives have been studied because of their potential applications in organic devices. These compounds have similarities to 2,2’-bipyridyl and 1,10-phenanthroline derivatives. They also exhibit unique reactivities and properties different from these compounds due to the fluorene moieties. The applications of 4,5-diazafluorenes have been widely investigated in various research fields to afford new functional materials such as electron-transporting materials, organic emitters, emissive complexes, sensing elements, solar sensitizers, and antibiotics. This article describes the chemistry and applications of 4,5-diazafluorenes.
Published online: 26th May, 2008
■ Synthesis and Properties of S-Aminothiiranium Salts of anti- and syn-9,9’-Bibenzonorbornenylidenes and 2,2’-Biadamantylidene
Yoshiaki Sugihara,* Rie Ohtsu, and Juzo Nakayama*
*Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan
Abstract
S-Aminothiiranium salts 5a-c of anti- and syn-9,9’-bibenzo- norbornenylidenes and 2,2’-biadamantylidene were synthesized by reacting thiiranes 3a-c with O-mesitylenesulfonylhydroxylamine. Decomposition of 5a and 5c in CD2Cl2 at rt yielded a mixture of the corresponding alkenes and thiiranes, whereas that of 5b yielded 1,2-thiazetidin-2-ium salts 8b. A CH2Cl2 solution of 8b was treated briefly with aq. NaHCO3 at 0 °C to produce N-unsubstituted 1,2-thiazetidine10b.
Published online: 29th May, 2008
■ Guanidine-Annelated Heterocycles XVI. A Practical Synthesis of 7-Chloro-4-phenylamino[1,2,4]triazoloquinazolin-5(4H)-ones
Wen-Chuan Hsu,* Pei-Wen Shan, Yi-Chen Huang, Kang-Chien Liu, and Tsu-Chung Chang*
*Department of Biochemistry, bPharmaceutical Research Institute, National Defense Medical Center, Taipei, Taiwan, R.O.C.
Abstract
The triazolo[2,3-a]quinazolin-5(4H)-ones 9a-c can be prepared via Dimroth rearrangement by treatment of 5 with representative carboxylic acid orthoesters 6a-c each heating at 40 °C more elevated temperature than the preparation of their analogous triazolo[4,3-a] isomers 7a-c.
Published online: 23rd May, 2008
■ Aldolisation and Carboxylation Reactions from α-Silyl-β-lactams. A Combined Theoretical and Experimental Study
Sabrina Parat, Béatrice Pelotier, Lycia Fournier, Michel Rajzmann, Philip J. Kocienski, and Jean-Marc Pons*
*Institut des Sciences Moléculaires de Marseille (ISM2), Aix-Marseille Université, UMR-CNRS 6263, Campus de St-Jérôme, service 532, F-13397 Marseille Cedex 20, France
Abstract
Treatment of α-silyl-β-lactam 3 with TBAF in the presence of an aldehyde or carbon dioxide leads, with total trans stereoselectivity, to the corresponding aldol or carboxy adducts 5-6. Semiempirical calculations account for this result.
Published online: 5th June, 2008
■ Synthesis, Structure and Photoluminescent Properties of Two Complexes Based on Iso-cyanuric Acid
Xifeng Lu, Jing Gao, Ligang Gai, Deliang Cui,* and Qilong Wang
*State Key Lab of Crystal Materials, Shandong University, Jinan 250100, P. R. China
Abstract
Two new complexes, [Cu2(C3N3O3H2)4]·H2O, I, and [Zn(C3N3O3H2)2(H2O)4]·C3N3O3H3·H2O, II, have been synthesized by the reactions of cyanuric chloride (C3N3Cl3), melamine (C3N6H6) with CuCl2·2H2O and ZnCl2, respectively, through hydrothermal route. They were characterized by single crystal diffraction, elemental analysis, thermalgravimetry analysis. Furthermore, the photoluminescent properties of both I and II were studied. In complex (I), the Cu(II) is two coordinated in a linear fashion by two nitrogen atoms. The Zn(II) atom in complex (II) is surrounded by two nitrogen atoms and four oxygen atoms to complete a six-coordinate environment. The combination of hydrogen bonds and π····π stacking interactions extends complex (I), (II) into three-dimension architectures.
Published online: 26th May, 2008
■ Reactivity of (R)-4-Phenyloxazolidine-2-thione Chiral Auxiliary: From Deprotection to Heterocyclic Interconversion
Jean-Christophe Monbaliu, Bernard Tinant, and Jacqueline Marchand-Brynaert*
*Unité de Chimie Organique et Médicinale, Département de Chimie, Université catholique de Louvain, Bâtiment Lavoisier, Place Louis Pasteur 1, B-1348 Louvain-la-Neuve, Belgium
Abstract
Using (R)-3-benzyl-4-phenyloxazolidin-2-thione (2) as model compound, a sequence of reactions has been established that allows the chiral auxiliary deprotection to furnish a primary amine. Treatment of 2 with ethyl triflate (3b) followed by ring opening with RbI (4b) and HI elimination with DBU, in a one pot process, gave S-ethyl-N-benzyl-N-1-phenylvinylcarbamothioate (5, 95% yield) which acid hydrolysis (9) and saponification liberated benzylamine. Through a mechanistic study, we showed that the activated chiral oxazolidin-2-thione 3b is a tunable intermediate towards the corresponding oxazolidin-2-one 7, thiazolidin-2-one 8 and thiazolidin-2-thione 10. All those reactions were chemoselective and preserved the chiral center. A structural analysis of this series of heterocycles, by NMR and X-ray diffraction, has been performed.
Published online: 9th June, 2008
■ Synthesis and Characterisation of Some New N-Glycosides Containing Substituted Pyridopyrimidinone, Pyrimidopyridazinone, Thiazolopyrimidinone and Quinolizin-4-one Moiety
Petr Simunek,* Jurij Svete, and Branko Stanovnik*
*University of Pardubice, Faculty of Chemical Technology, Department of Organic Chemistry, Nám. Cs. Legií565, CZ 532 10 Pardubice, Czech Republic
Abstract
A series of new N-glycosides (D-glucosides, D-mannosides, L- and D-arabinosides, D-xylosides and one D-galactoside) containing heterocyclic moiety have been prepared by reaction of the corresponding heterocyclic amines with pyranoses in boiling methanol. The structures of the prepared compounds have been studied by means of proton and carbon NMR spectroscopy. In the most cases the products existed in DMSO solution as the single anomers.
Published online: 29th May, 2008
■ Reactions of Alkylation of Biologically Interesting Triazolo[4,5-g]quinolines and Triazolo[4,5-g]quinoline-1-oxides with Electrophilic Reagents
Antonio Carta,* Angela Sias, Sandra Piras, and Giuseppe Paglietti
*Department of Medicinal and Toxicological Chemistry, University of Sassari, Via Muroni 23, 07100 Sassari, Italy
Abstract
With the aim to improve the biological activities discovered for compounds containing the triazolo[4,5-g]quinoline nucleus, we describe the chemical behaviour of 4-chlorotriazolo[4,5-g]quinolines (1a,b) and some its triazolo-N1-oxide derivatives (1c-e and II) with electrophilic reagents in order to optimize the synthetic pathways for obtaining both mixtures of N1,2,3-alkyl isomers and selectively N1-O-alkyl derivatives.
Published online: 9th June, 2008
■ Benzo[b]-1,10-phenanthrolines. V. Synthesis and Properties of 3,3’-Polymethylene-2-(pyrid-2’-yl)benzo[b]-1,10-phenanthrolines
A. F. M. Motiur Rahman and Yurngdong Jahng*
*College of Pharmacy, Yeungnam University, Gyeongsan 712-749, Korea
Abstract
A series of 3,3’-polymethylene-2-(pyrid-2’-yl)benzo[b]-1,10- phenanthrolines were prepared by the Friedländer reactions of 4-aminoacridine-3-carbaldehyde with pyrido[b]cycloalkanones as potential tridentate ligands. Dehydrogenation of dimethylene-bridged system afforded the corresponding fully aromatized system. Flexibility of annulated bridges is highly dependent on the length of the carbon chain, where the tetramethylene-bridge is rigid enough to differentiate eight bridge protons in 1H NMR time scale at rt.
Published online: 12th June, 2008
■ Friedländer Quinoline Synthesis Catalyzed by M(HSO4)n (M=Al, Mg, Ca) under Solvent-Free Conditions
Khodabakhsh Niknam,* Mohammad Ali Zolfigol, and Amin Dehghani
*Chemistry Department, Faculty of Sciences, Persian Gulf University, Bushehr 75169, Iran
Abstract
Polysubstituted quinolines were synthesized from the 2-aminobenzophenone, ethylacetoacetate or ketones in the presence of metal hydrogen sulfates [M(HSO4)n] in good to high yields at 70 °C under solvent-free conditions.
Published online: 12th June, 2008
■ Green Approach for the Efficient Synthesis of Quinolines Promoted by Citric Acid
Ramu Enugala, Sreelatha Nuvvula, Vijay Kotra, Ravi Varala, and Srinivas R. Adapa*
*I&PC Division, Indian Institute of Chemical Technology, Hyderabad, India-500 007
Abstract
Citric acid promoted Friedlander synthesis of a mini-library of poly substituted quinolines (30 examples) at 100 °C under solvent-free conditions was achieved in moderate to excellent yields (54-99%). The method is simple, cost-effective and environmentally benign.
Published online: 29th May, 2008
■ Kopreasin A, a New Indole Alkaloid from Kopsia arborea
Kazumasa Zaima, Yosuke Matsuno, Yusuke Hirasawa, Abdul Rahman, Gunawan Indrayanto, Noor Cholies Zaini, and Hiroshi Morita*
*Faculty of Pharmaceutical Sciences, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
Abstract
A new alkaloid, kopreasin A (1) was isolated from the leaves of Kopsia arborea (Apocynaceae) together with ten known indole alkaloids (2 - 11), and the structure was elucidated by NMR spectral analysis using 2D techniques. These indole alkaloids showed a moderate vasorelaxant activity on isolated rat aorta ring.
Published online: 2nd June, 2008
■ β-Ketoesters Derived from Pyroglutamic Acid: New Entry to Hydroxylated Pyrrolizidinones
Géraldine Le Bouc, Christine Thomassigny, and Christine Greck*
*Université de Versailles St-Quentin-en-Yvelines, Institut Lavoisier de Versailles-UMR CNRS 8180, 45 Av. des Etats Unis, 78035 Versailles CEDEX, France
Abstract
Four hydroxylated pyrrolizidinones have been obtained from β-ketoesters derived from L-pyroglutamic acid or 4-(R)-hydroxy-L-pyroglutamic acid. The asymmetric hydrogenations, in the presence of BinapRuBr2 catalysts, of such β-ketoesters bearing pyrrolidinones proceeded with high diastereomeric excesses leaving to a complete control of the absolute configuration at the C7 hydroxylated carbon atom of the azabicycles.
Published online: 2nd June, 2008
■ Synthesis of Novel 3,6-Disubstituted Furo[2,3-d]pyrimidines
Mehdi Bakavoli,* Mohammad Rahimizadeh, and Zinat Gordi
*Department of Chemistry, School of Sciences, Ferdowsi University of Mashhad, Mashhad, 91775-1436, Iran
Abstract
One-pot base catalyzed heterocyclization of 2-amino-5-phenyl-3-furancarbonitrile with various isothiocyanates afforded the novel furo[2,3-d]pyrimidine derivatives in high yields.
Published online: 12th June, 2008
■ Synthesis of 1(3H)-Iminobenzo[c]thiophene Derivatives by Hydriodic Acid-Mediated Cyclization of 2-(Vinyl)thiobenzamide Derivatives
Kazuhiro Kobayashi,* Seiki Fujita, and Hisatoshi Konishi
*Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan
Abstract
Secondary 2-(vinyl)thiobenzamide derivatives, easily prepared by reacting 2-lithiostyrene derivatives with various isothiocyanates, undergo intramolecular cyclization on treatment with concentrated hydriodic acid to produce 1(3H)-iminobenzo[c]thiophene derivatives in fair-to-good yields. Some of them have been hydrolyzed under acidic conditions to afford benzo[c]thiophen-1(3H)-one derivatives in good yields.