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
Barry M. Trost's Special Issues, Vol. 67, No. 1, 2006
Published online: 26th August, 2005
■ Preparation of Nα-Acetyl-Nε-3-(methylpyridinium)lysine (MP-lysine) as a Hapten of Antibody
Kohsaku Matsumoto, Takuya Kumamoto, Tsutomu Ishikawa,* Erika Ishii, Hideyuki Tomitori, and Kazuei Igarashi
*Graduate School of Pharmaceutical Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
Abstract
The title compound was prepared from α-tert-butyl Nα-tert-butoxycarbonyl-L-glutamate (Boc-Glu-OBu-t) by N-alkylation of 3-methylpyridine after one carbon-elongation through six steps.
Published online: 13th September, 2005
■ Stereoselective Synthesis of Tetrahydrofuran by Diasteroselective [3+2] Cycloaddition Reaction of Chiral Allylsilane with α-Keto Ester
Takahiko Akiyama,* Shinya Funaki, and Kohei Fuchibe
*Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
Abstract
Lewis acid mediated [3+2] cycloaddition reaction of chiral allylsilane, bearing a stereogenic center on the silyl substituents, with ±-keto ester gave silyl-substituted tetrahydrofurans with good to high stereoselectivity.
Published online: 14th March, 2005
■ Chiral Complexation of Multidentate N-Heterocyclic Podand Ligands Bearing Histidyl Moieties
Toshiyuki Moriuchi, Masahito Nishiyama, Kazuhiro Yoshida, and Toshikazu Hirao*
*Department of Applied Chemistry, Graduate School of Science, Osaka University, 2-1 Yamadaoka, Suita, Osaka 560-0871, Japan
Abstract
Preorganized left- and right-handed helical conformations of the chiral pentadentate N-heterocyclic ligands bearing the podand histidyl moieties, N,N’-bis{(S)-(+)-1-methoxycarbonyl-2-(4-imidazoyl)ethyl}-2,6-pyridinedicarboxamide (L-BHisPA) and the D-isomer (D-BHisPA), induce the chiral complexation through spiral coordination of the pentadentate BHisPA to Cu(II) center to give L- and D-BHisPA-Cu(II) as a ∧ and Δ enantiomorph, respectively. Each complex is connected by continuous intermolecular hydrogen bonds in a solid state to form a hydrogen-bonded macrocycle with left- or right-handed windmill-like arrangement, respectively. In the case of the Cu(II) complex (L-HisPA-Cu(II)) with the ligand bearing one histidyl pendant group, {(S)-(+)-1-methoxycarbonyl-2-(4-imidazoyl)ethyl}-2-pyridinecarboxamide (L-HisPA), each molecule is assembled in a solid state by continuous intermolecular hydrogen bonds and π-π interaction.
Published online: 24th March, 2005
■ Regioselectivity in the Biaryl Coupling Reactions of 1-[(1,3-Benzodioxol-5-yl)methyl]-7-iodo-2,3-dihydroindole Using Palladium Reagent
Takashi Harayama,* Akihiro Hori, Hitoshi Abe, and Yasuo Takeuchi
*Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan
Abstract
The biaryl coupling reaction of 1-[(1,3-benzodioxol-5-yl)methyl]-7-iodo-2,3-dihydroindole (1) using Pd(OAc)2 gave selectively 4,5-dihydro-7H-[1,3]dioxolo[4,5-k]pyrrolo[3,2,1-de]phenanthridine (4), which was formed by connection to a more hindered carbon, in 3.4~4.2:1 ratios.
Published online: 22nd April, 2005
■ Complexation of Diphenyl(tetrafluoroborato)-λ3-iodane with Pyridines
Takashi Suefuji, Motoo Shiro, Kentaro Yamaguchi, and Masahito Ochiai*
*Faculty of Pharmaceutical Sciences, University of Tokushima, Sho-machi, Tokushima 770-8505, Japan
Abstract
Diphenyl(tetrafluoroborato)-λ3-iodane forms 1:1 complexes with pyridine-derived ligands in CD2Cl2 solution and the binding constants decrease in the order: 1,10-phenanthroline > 2,2’:6’,2”-terpyridine > 2,2’-bipyridyl Å` pyridine. The 1:1 complex of the λ3-iodane with pyridine adopts a distorted square-planar geometry around the iodine atom.
Published online: 15th July, 2005
■ Formation of 4’,5’-Didehydro-5’-deoxy-3’-O-methyluridine via Regioselective Nucleophilic Addition of Methoxide Anion to 2’,3’-Anhydro-5’-dehydro-5’-iodouridine
Hironao Sajiki,* Hideki Takasu, and Kosaku Hirota*
*Laboratory of Medicinal Chemistry, Gifu Pharmaceutical University, 6-1 Mitahora-higashi 5-chome, Gifu 502-8585, Japan
Abstract
Treatment of 2’,3’-anhydro-5’-deoxy-5’-iodouracil (1) with sodium methoxide regioselectively provided 4’,5’-didehydro-5’-deoxy-3’-O-methyluridine (2) as the sole product via 4’,5’-didehydro-5’-deoxy-2’,3’-epoxyuridine (6) as an intermediate.
Published online: 15th July, 2005
■ A Concise Synthesis of (+)-Indolizidine 209D Using a C2-Symmetric 2,6-Diallylpiperidine
Hiroki Takahata* and Motohiro Ichinose
*Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
Abstract
An asymmetric synthesis of (+)-indolizidine 209D (2) using C2-symmetric 2,6-diallylpiperidine (1) as a chiral building block is presented in a straightforward fashion.
Published online: 13th September, 2005
■ 1,3-Dipolar Cycloadditions of 2-tert-Butoxycarbonyl-1-pyrroline N-Oxide with Chiral Acrylates and Acrylamides
Federica Pisaneschi, Martina Gensini, Maria Salvati, Franca M. Cordero, and Alberto Brandi*
*Dipartimento di Chimica Organica “Ugo Schiff”, Università di Firenze, Via della Lastruccia n. 3, I-50019 Sesto Fiorentino (Fi), Italy
Abstract
The 1,3-dipolar cycloadditions of a series of chiral acrylates and acrylamides with 2-tert-butoxycarbonyl-1-pyrroline N-oxide were studied. The synthesis of enantiopure tert-butyl (2R,7aR)- and (2S,7aS)-2-hydroxy-3-oxo-tetrahydro-1H-pyrrolizine-7a(5H)-carboxylates starting from the acryloyloxazolidinone derived from (S)-phenylalanine is reported.
Published online: 13th September, 2005
■ Facile Synthesis of (S)-5,5-Difluoronorleucine and Its Incorporation in Biologically Active Peptides as an Methionine Mimetic
Satoshi Osada,* Takako Ishimaru, Hiroshi Kawasaki, and Hiroaki Kodama
*Faculty of Science and Engineering, Saga University, Honjo 1, Saga, Saga 840-8502, Japan
Abstract
Both Boc and Fmoc protected 5,5-difluoronorleucines (F2Nle) were easily prepared from commercially available amino acid derivatives. F2Nle can be viewed as a mimic of methionine in which the sulfur atom is replaced by the CF2 moiety. Two analogues of methionine-containing biologically active peptides (fMLP and Met-enkephalin) were prepared. The validity of CF2-substituted methionine analogues was confirmed in their biological assay.
Published online: 13th September, 2005
■ A New and Convenient Access to Enantiopure C2-Symmetric 2,5-Diethynylpyrrolidine
Ikki Yonemura, Noriyuki Yasuda, Toshio Kawanami, Takeshi Hanamoto, Hiroshi Furuno, and Junji Inanaga*
*Institute for Fundamental Research of Organic Chemistry, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
Abstract
Both (2R,5R)- and (2S,5S)-diethynylpyrrolidines were conveniently synthesized from 3,6-bis(mesyloxy)-1,7-octadiyne in optically pure forms via (R)-1-(4-methoxyphenyl)ethylamine-induced pyrrolidine ring formation, chromatographic separation of the corresponding diastereomers, and cleavage of the benzylic C-N bond.
Published online: 13th September, 2005
■ Synthesis and Complexation Properties of (Tropon-2-yl)monoaza-18-crown-6 Ethers
Zhegang Huang, Xiaopeng Zhang, Zhiqi Cong, Bingzhu Yin,* and Kimiaki Imafuku*
*Department of Chemistry, Faculty of Science, Kumamoto University, Kurokami 2-39-1, Kumamoto 860-8555, Japan
Abstract
Four (tropon-2-yl)monoaza-18-crown-6 ethers (3a-d) were prepared by the reactions of 2-methoxytropones (1a-d) with monoaza-18-crown-6 (2) in moderate yields. The UV-VIS spectra of these monoazacrown ethers (3a-d) were dramatically changed by adding metal salts. The complexations with moderately hard cations (Ba2+ and Pb2+) were more effectively occurred than those with hard cations (Ca2+, Na+, K+, and Cs+) and with soft cations (Hg2+ and Cd2+).
Published online: 8th September, 2005
■ Criss-cross Cycloaddition Reactions with Hexafluoroacetone Azine. Mechanism and Some Synthetic Applications
Klaus Burger,* Lothar Hennig, Olaf Zeika, and Andrea Lux
*Department of Organic Chemistry, University of Leipzig, Johannisallee 29, D-04103 Leipzig, Germany
Abstract
Using hexafluoroacetone azine as model compound we have shown that azomethine imines are the [1.1]intermediates of the criss-cross cycloaddition. The readily available trifluoromethyl substituted azomethine imines are reactive species exhibiting considerable synthetic potential for the construction of partially fluorinated heterocycles and polymers.
Published online: 26th August, 2005
■ gem-Diamine 1-N-Iminosugars, a New Family of Glycosidase Inhibitors: Synthesis and Biological Activity
Yoshio Nishimura
*Institute of Microbial Chemistry, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
Abstract
Specific inhibitors of glycosidases are useful for unraveling how glycoconjugates regulate biological functions, and also for developing the new drugs for the serious diseases associated with both the biosynthesis and the degradation of glycoconjugate such as cancer, tumor metastasis, inflammatory disorders, viral and bacterial infections and so forth. This article describes the synthesis and biological activity of gem-diamine 1-N-iminosugars, a new class of glycosidase inhibitors, with a nitrogen atom in place of the anomeric carbon. New inhibitors that may mimic the glycopyranosyl cation, the putative intermediate of enzymatic glycosidic hydrolysis, have shown strong and specific inhibition against glycosidases. The inhibitors also illustrate a promising candidate of new drugs for tumor metastasis.