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
Ivar Ugi's Special Issues, Vol. 73, No. 1, 2007
Published online: 9th October, 2007
■ Synthesis of Isodecarine
Jakub Styskala, Petr Cankar, Miroslav Soural, Jan Hlavac,* Pavel Hradil, Jaroslav Vicar, and Vilim Simanek
*Department of Organic Chemistry, Faculty of Science, Palacky University, Tr. Svobody 8, 771 46 Olomouc, Czech Republic
Abstract
The cyclization of 3-bromo-6-methoxy-2-(naphtho[2,3-d][1,3]dioxol-5-ylaminomethyl)phenol (2) using tributyltinhydride under radical-mediated conditions was accompanied by spontaneous oxidation and afforded directly isodecarine (2-methoxy[1,3]benzodioxolo[5,6-c]phenanth-ridin-1-ol, (3). 2-Methoxy-6-(naphtho[2,3-d][1,3]dioxol-5-ylaminomethyl)-phenol (4) was isolated as a side product. Isodecarine was also prepared by the catalytic debenzylation of 7-benzyloxy-8-methoxy-2,3-methylendioxybenzo-[c]phenanthridine (5). This compound was efficiently converted to 7-benzyloxy-8-methoxy-5-methyl-2,3-methylenedioxybenzo[c]phenanthridi-nium trifluoromethanesulfonate (6) in high yield and with a short reaction time.
Published online: 7th September, 2007
■ Synthesis of Thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-ones via Their [1,2,4]Triazolo[4,3-c]pyrimidine Compounds as New Ring Systems by Dimroth-Type Rearrangement
Tomohisa Nagamatsu,* Shoeb Ahmed, Abugafar M. L. Hossion, and Seiji Ohno
*Department of Drug Discovery and Development, Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1, Tsushima-naka, Okayama 700-8530, Japan
Abstract
General and facile syntheses of thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-one (6a) and its 2-substituted derivatives (6b-j) produced by instantaneous isomerization of their [4,3-c] compounds (7a-j), which were prepared by condensation of 4-hydrazinothieno[2,3-d]pyrimidin-2(1H)-one (10) with appropriate triethyl orthoesters or by oxidative cyclization of 4-(benzylidenehydrazino)thieno[2,3-d]pyrimidin-2(1H)-ones (11c-j), are described as novel ring systems and as a new class of potential xanthine oxidase inhibitors. The [1,5-c] isomers (6a-c) were further prepared by condensation of 3-amino-4-imino-2-oxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidine (14) with appropriate triethyl orthoesters as a synthetic method for a reliable structure of the tricyclic ring systems.
Published online: 18th September, 2007
■ One-Pot Formation of Functionalised 2-Piperidinones from Arylidenecyanoacetates and Methanolic Ammonia via Tandem Reactions
Manas Chakrabarty,* Sulakshana Karmakar, Shiho Arima, and Yoshihiro Harigaya
*Department of Chemistry, Bose Institute, 93/1, A.P.C. Road, Kolkata 700009, India
Abstract
Aryl aldehydes react with ethyl cyanoacetate in methanolic ammonium acetate to expeditiously furnish, besides high yields of arylidenecyanoacetates, 4,6-diaryl-3,5-dicyano-5-ethoxycarbonyl-2-piperidinones in low yields. But preformed arylidenecyanoacetates react with methanolic ammonia to furnish the same functionalised 2-piperidinones in much better yields. The actual stereostructure of one of the products was determined by single crystal X-ray diffraction analysis, and novel tandem reactions occurring in one pot are proposed for the formation of the products.
Published online: 7th September, 2007
■ Some Reactions of O-Equatorial Spirophosphoranes Bearing the Bidentate Ligand Based on Decafluoro-3-phenyl-3-pentanol
Xin-Dong Jiang, Shiro Matsukawa, Hideaki Yamamichi, and Yohsuke Yamamoto*
*Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima 739-8526, Japan
Abstract
Some reactions of O-equatorial and O-apical methylphosphoranes bearing two bidentate ligands consisted of 1,1,1,2,2,4,4,5,5,5-decafluoro- 3-phenyl-3-pentanol were examined. Not only the O-apical phosphorane, but also the O-equatorial isomer did not react with MeLi as a nucleophile at the phosphorus center. This should be due to the steric bulkiness of the C2F5 group. For both isomers, deprotonation at the methyl group was achieved using Superbase (t-BuOK/n-BuLi) to give the corresponding α-anion, which was treated with several electrophiles to afford new phosphorane derivatives. The O-equatorial and O-apical phosphoranes having a β-hydroxyethyl group as the monodentate ligand were synthesized. It was found that under basic conditions, the O-apical phosphorane could be converted into the O-equatorial isomer via hexacoordinate phosphate intermediates.
Published online: 2nd October, 2007
■ Heterocyclic Amide Hydraphile Synthetic Cation Transporters
Wei Wang, Carl R. Yamnitz, and George W. Gokel*
*Departments of Chemistry & Biochemistry and Biology, Center for Nanoscience, University of Missouri - Saint Louis, One University Boulevard, Saint Louis, MO 63121 USA
Abstract
A family of hydraphile ionophores has been prepared in which various ~CH2N~ to ~CON~ replacements have been made to assess the effect on Na+ transport through phospholipid bilayers. When the central relay (see graphical abstract) was a third macrocycle, symmetrical carbonyl for methylene replacements enhanced activity, but the presence of four or six amide residues diminished transport. When a pair of amides was incorporated into compounds having a 4,4‘-bipiperidyl central relay, both significant increases and decreases were observed depending upon the amide positions. The presence of amides alters both the donor group type and strength and the conformation of the structural unit in which it occurs. These changes are shown to depend on the liposomes in which the Na+ release studies were conducted. These changes are shown to affect the toxicity of the hydraphiles to E. coli.
Published online: 25th September, 2007
■ Synthesis of a 16-Triazole Phorboxazole A Analog via Intramolecular Triazole Formation
Lu Ying and Craig J. Forsyth*
*Department of Chemistry, The Ohio State University, 100 W 18th Ave., Columbus, OH, 43210, USA
Abstract
The intramolecular formation of a triazole using a Cu(I)-catalyzed Huisgen [3+2]-cycloaddition between an organic azide and terminal alkyne enabled the preparation of a C16-C18 triazole analog of phorboxazole A.
Published online: 25th July, 2007
■ Synthesis of Optically Pure 4-Hydroxymethyl-3-phenoxy-2-azetidinone from D-Glucal
Pilar Areces,* Esther Carrasco, Maria Monterde, Mark E. Light, and Joaquín Plumet*
*Department of Organic Chemistry, Faculty of Chemistry, University Complutense, 28040-Madrid, Spain
Abstract
A convenient approach to enantiomerically pure 4-hydroxymethyl- 3-phenoxy-2-azetidinone has been carried out using the easily available aldehyde 5 as chiral starting material.
Published online: 3rd August, 2007
■ Natural Product Inspired meta/para’-Biaryl Ether Lactam Macrocycles by Double Ugi Multicomponent Reactions
Bernhard Westermann, Dirk Michalik, Angela Schaks, Oliver Kreye, Christoph Wagner, Kurt Merzweiler, and Ludger A. Wessjohann*
*Leibniz Institute of Plant Biochemistry, Department of Bioorganic Chemistry, Weinberg 3, 06120 Halle, Germany
Abstract
Isonitrile meta/para’-functionalized biaryl ethers can serve as key building blocks for the highly efficient and diverse one step production of natural product inspired peptide/peptoid macrocycles, thereby forming up to 54-membered rings with eight or even sixteen new bonds. Aliphatic diamine and diacid tethers give access to two different classes of biaryl ether cyclopeptoids, either with exo/endo or exclusively endo dipeptidic moieties.
Published online: 10th August, 2007
■ Heterocycles from Ylides. Part X. Synthesis of 3-Hydroxy-2,3-dihydroindoles by a Domino Reaction
Giuseppe Cremonesi, Piero Dalla Croce,* Francesco Fontana, and Concetta La Rosa
*Department of Organic and Industrial Chemistry, C.N.R. - I.S.T.M., Via Venezian 21, I-20133 Milano, Italy
Abstract
A domino reaction between 2-N-phenylsulfonylaminobenzaldehyde (1) and sulfonium ylides (2) leads to 3-hydroxy-2,3-dihydroindoles (3) whose structure was confirmed on the basis of analytical and spectroscopic data.
Published online: 17th August, 2007
■ Diastereoselective Synthesis of 6-Bromo-6-(1-hydroxyethyl)penicillanate by Cross-Coupling of 6,6-Dibromopenicillanate and Acetaldehyde Promoted with Grignard Reagents: Role of Amine Ligands
Manabu Kuroboshi, Keiko Mesaki, Syoichi Tateyama, and Hideo Tanaka*
*Department of Applied Chemistry, Faculty of Engineering, Okayama University, Tsushima-naka 3-1-1, Okayama 700-8530, Japan
Abstract
Grignard reagent-promoted coupling reaction of diphenylmethyl 6,6-dibromopenicillanate 1b with acetaldehyde in the presence of N,N,N’,N”,N”-pentamethyldiethylenetriamine took place in a highly diastereoselective manner to give diphenylmethyl (1’R,3S,5R,6S)-6-bromo-6-(1’-hydroxyethyl)penicillanate 2b effectively, which is a potent intermediate for the synthesis of carbapenem antibiotics.
Published online: 14th September, 2007
■ Nitrogen 14 NMR and Correlations of Oxidation Potentials of Dibenzo[a,d]cycl[2.2.3]azines with the Corresponding HOMOs: Further Evidence for Peripheral Conjugate System
Kiyoshi Matsumoto,* Hirokazui Iida, Seisuke Mimori, Hiroshi Hamana, and Takane Uchida
*Faculty of Pharmacy, Chiba Institute of Science, Shiomi-cho 15-8, Choshi, Chiba 288-0025, Japan
Abstract
For the first time, 14N NMR spectra of a novel type of heterocycles, dibenzo[a,d]cycl[2.2.3]azines were described. The chemical shifts are almost independent of substituents at position 2. The correlations of oxidation potentials with HOMO energies of dibenzo[a,d]cycl[2.2.3]azines also offer very good correlation coefficients (r2>0.92) regardless of calculation methods at various levels. Thus, it was concluded that the contribution of the unshared electron pairs of the central nitrogen to the peripheral conjugation in this system is almost negligible.
Published online: 2nd October, 2007
■ Lipid Analogs of the Nodulation Factors Using the Ugi/Passerini Multicomponent Reactions: Preliminary Studies on the Carbohydrate Monomer
Nathalie Grenouillat, Boris Vauzeilles, and Jean-Marie Beau*
*Université Paris-Sud 11, Institut de Chimie Moléculaire et des Matériaux associé au CNRS, Laboratoire de Synthèse de Biomolécules, 91405 Orsay Cedex, France
Abstract
Treament of 1,3,4,6-tetra-O-acetyl-2-deoxy-2-isocyano-β-D-glucopyranose and the corresponding β-allyl glycoside with octanal and acetic acid provide the Passerini products in excellent yields whereas the corresponding Ugi transformation in the presence of i-propylamine proceeded with much lower efficiency. This work represents a preliminary investigation on a project directed towards the modification of the lipid moiety of the nodulation factors.