Special Issue

Ryoji Noyori's Special Issues, Vol. 76, No. 1, 2008

76 data found. 31 - 60 listedFirst Previous Next Last
Paper | Special issue | Vol 76, No. 1, 2008, pp. 305 - 311
Published online: 22nd February, 2008
DOI: 10.3987/COM-08-S(N)9
Synthesis of Chiral Tetrahydroisoquinoline-Derived β-Amino Alcohols and Their Application to Asymmetric Reaction

Yoshiyuki Hari, Masaki Sakuma, Ayako Miyakawa, Keiichiro Hatano, and Toyohiko Aoyama*

*Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanbe-dori, Mizuho, Nagoya 467-8603, Japan


Three chiral 1,2,3,4-tetrahydroisoquinoline-derived β-amino alcohols were synthesized by using the Ru-catalyzed asymmetric transfer hydrogenation of 6-methoxy-1-(2-methoxyphenyl)-3,4-dihydroisoquinoline as the key reaction. The ability of the synthesized β-amino alcohols as chiral ligands was evaluated in the addition of diethylzinc to benzaldehyde.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 313 - 320
Published online: 15th February, 2008
DOI: 10.3987/COM-08-S(N)10
Macropyllanosides A - D, Secoiridoid Glycosides from Hydrangea macrophylla subsp. serrata

Masao Kikuchi,* Rie Kakuda, and Yasunori Yaoita

*Department of Molecular Structural Analysis, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi 981-8558, Japan


Four new secoiridoid glycosides, named macrophyllanosides A - D, were isolated from the leaves of Hydrangea macrophylla subsp. serrata. Their structures have been determined by spectroscopic and chemical means.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 321 - 328
Published online: 14th March, 2008
DOI: 10.3987/COM-08-S(N)11
Study of Synthetic Routes for the Spiroketal Fragment in Calyculin A Based on Conformational Analysis

Takatoshi Matsumoto,* Mototsugu Kabeya, Eiichi Morishita, and Takayuki Shioiri

*Institute of Multidsciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba, Sendai 980-8577, Japan


The conformational analysis of the spiroketal fragment of calyculin A revealed that a series of the Wittig reaction by way of the Swern oxidation was suitable for the addition of the C1-unit for the preparation of the spiroketal fragment. It also clarified that failure in the reaction of cyanide and the tetraol equivalents was attributed to the steric and electrostatic effects of the symmetrical structures.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 329 - 351
Published online: 11th March, 2008
DOI: 10.3987/COM-08-S(N)13
Stereoselective Preparation and Cope Rearrangement of 2-CF3-cis-2,3-bis(alkenyl)oxiranes: A Facile Route to 2-CF3-Substituted Oxacycles

Masaki Shimizu,* Takuya Fujimoto, Xinyu Liu, Youhei Takeda, and Tamejiro Hiyama*

*Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo-ku, Kyoto 615-8510, Japan


We describe here a facile route to 2-trifluoromethyl-substituted 4,5-dihydrooxepins, which involves stereoselective preparation and Cope rearrangement of 2-trifluoromethyl-cis-2,3-bis(alkenyl)oxiranes. Treatment of 1,1-dichloro-2-hydroxy-2-trifluoromethylalk-3-enes with alkenyllithium and then lithium 2,2,6,6-tetramethylpiperidide generated cis-2,3-bis(alkenyl)-2-lithio-3- trifluoromethyloxiranes, which reacted with a variety of electrophiles to give the corresponding tri- and tetrasubstituted oxiranes stereoselectively. Cope rearrangement of the cis-oxiranes proceeded upon heating, giving rise to 2-trifluoromethyl-substituted 4,5-dihydrooxepins in high to excellent yields. The Cope rearrangement is found remarkably accelerated by the presence of such metal substituents as boryl, silyl, and stannyl groups at 7-position, that can act as versatile functionalities for further elaboration of the ring-enlarged products. Subsequent reduction and oxidation of the rearranged products gave 2-trifluoromethylated oxepanes and oxepins in good yields.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 353 - 380
Published online: 18th March, 2008
DOI: 10.3987/COM-08-S(N)14
The Octaethylporphyrin-Dihexylbithiophene Derivatives Combined with Pyridine and Pyrimidine Rings. Their Syntheses and Proton-Mediated and Heat-Driven Spectral Changes

Hiroyuki Higuchi,* Naoto Hayashi, Takuya Matsukihira, Takanori Kawakami, Toru Takizawa, Junji Saito, Keiko Miyabayashi, and Mikio Miyake

*Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan


The octaethylporphyrin (OEP)-dihexylbithiophene (DHBTh) derivatives combined with pyridine (Pyr) and pyrimidine (Pym) as proton-acceptable rings (PAR) were synthesized, describable as OEP-DHBTh-PAR, in which all the OEP, DHBTh, and PAR components are connected with diacetylene linkage. Their 1H NMR and electronic spectral properties and electrochemical behaviors were studied under the neutral and acidic conditions. Reversible proton-mediated and heat-driven spectral changes of OEP- DHBTh-PAR were performed, reflecting both properties of PAR and DHBTh.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 381 - 390
Published online: 21st April, 2008
DOI: 10.3987/COM-08-S(N)19
Chiral Cationic Pd-Phosphinooxazolidine Catalysts for a Highly Efficient Asymmetric Diels-Alder Reaction in Ionic Liquids

Hiroto Nakano,* Yasuhiro Nishiuchi, Kouichi Takahashi, Reiko Fujita, Koji Uwai, and Mitsuhiro Takeshita*

*Tohoku Pharmaceutical University, 4-4-1, Komatsushima, Aoba-ku, Sendai 981-8558, Japan


Chiral cationic palladium-phosphinooxazolidine catalysts in ionic liquid afforded good to excellent enantioselectivity in Diels-Alder reactions. The catalyst was recycled three times in ionic liquid (85-90%, 71-88% ee) or seven times in a mixed ionic liquid/CH2Cl2 (91-94%, 91-94% ee).

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 391 - 399
Published online: 25th March, 2008
DOI: 10.3987/COM-08-S(N)20
Preparation of New Nitrogen-Bridged Heterocycles. 63. Unexpected Formation of Thieno[3’,4’:4,5]imidazo[1,2-a]pyridines

Akikazu Kakehi,* Hiroyuki Suga, Atsushi Izumita, and Takashi Abe

*Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Wakasato, Nagano 380-8553, Japan


The alkaline treatment and dehydrogenation of pyridinium salts, obtainable from the S-alkylation of 3,5-dimethylpyridinium 2-alkylthio-1-cyano-2-thioxoethylides with some phenacyl bromides, afforded unexpected heterocycles, 3-alkylthio-1-arylcarbonyl-6,8-dimethylthieno[3’,4’:4,5]imidazo[1,2-a]pyridines, together with the corresponding 2-alkylthio-1-arylcarbonylthio- 6,8-dimethylindolizine-3-carbonitriles.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 401 - 428
Published online: 4th April, 2008
DOI: 10.3987/COM-08-S(N)21
Synthesis of 1,2,4-Trisubstituted Imidazoles and 1,3,5-Trisubstituted 1,2,4-Triazoles

Corinne Baumgartner, Lukas Brändli, and François Diederich*

*Laboratorium für Organische Chemie, ETH Zürich, Hönggerberg, HCI, CH-8093 Zürich, Switzerland


We report synthetic strategies to easily access 1,2,4-trisubstituted imidazoles by introduction of different residues at C(2) and C(4) followed by substitution at N(1). Furthermore, a synthesis of trisubstituted 1,2,4-triazoles via a cyclization of hydrazonamides is described.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 429 - 438
Published online: 8th April, 2008
DOI: 10.3987/COM-08-S(N)23
Ruthenium Tetroxide Oxidation of N-Acyl Cyclic Amine-2-phosphonic Acid Diesters

Mamoru Kaname, Hironori Mashige, Shigeyuki Yoshifuji, and Haruki Sashida*

*Faculty of Pharmaceutical Sciences, Hokuriku University, Kanagawa-machi, Kanazawa 920-1181, Japan


The utility of the ruthenium tetroxide (RuO4) oxidation of N-acyl cyclic amine-2-phosphonic acid esters was investigated. The oxidation of the N-protected cyclic amines (4, 5) having a phosphono diester group under the standard double layer condition of ethyl acetate-water using a catalytic amount of RuO2 and excess NaIO4 produce the corresponding lactams in good yields. The obtained lactam phosphono diesters (6, 7) were readily converted into the ω-amino-ω-phosphonocarboxylic acids (10, 11).

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 439 - 453
Published online: 17th April, 2008
DOI: 10.3987/COM-08-S(N)25
A Facil and Efficient Synthesis of Mono- and Bis-functionalized meso-Substituted Porphyrins via Palladium-Catalyzed Negishi Cross-Coupling

Toshikatsu Takanami,* Miku Yotsukura, Wakaba Inoue, Naoyuki Inoue, Fumio Hino, and Kohji Suda*

*Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo 204-8588, Japan


A series of mono- and bis-functionalized meso-substituted porphyrins bearing chemically reactive functional groups such as -COOR, -Cl, and -CN in the alkyl substituents at the meso positions were efficiently synthesized by the reactions of meso-brominated precursors with alkylzinc reagents via palladium-catalyzed Negishi cross-coupling.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 455 - 469
Published online: 8th April, 2008
DOI: 10.3987/COM-08-S(N)30
Synthetic Studies on Mycobacterium tuberculosis Specific Fluorescent Park’s Nucleotide Probe

Kai Li and Michio Kurosu*

*Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523-1682, USA.


An efficient synthesis of N-glycolyl Park’s nucleotide, a Mycobacterium tuberculosis (Mtb) specific peptidoglycan precursor, analog-fluorescein conjugate, is achieved. A fluorescent conjugated Mtb Park’s nucleotide analog 5 would be a very useful probe for the characterization of Mtb MraY, catalyzing the biosynthesis of lipid I from UDP-N-acyl-Mur-pentapeptide, and for the development of high-throughput screening (HTS) for Mtb MraY inhibitors.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 471 - 483
Published online: 17th April, 2008
DOI: 10.3987/COM-08-S(N)32
Silver-Catalyzed Synthesis of 1,2-Dihydroisoquinolines through Direct Addition of Carbon Pronucleophiles to ortho-Alkynylaryl Aldimines

Naoki Asao,* Salprima Yudha S., Tsutomu Nogami, and Yoshinori Yamamoto

*Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan


AgOTf-catalyzed reaction of ortho-alkynyl-arylaldimines with various kinds of pronucleophiles afforded a variety of 1,2-dihydroisoquinoline derivatives in good to high yields. Treatment of ortho-alkynyl-arylaldimines with a stoichiometric amount of AgOTf, followed by the protonation with TfOH produced isoquinolinium trifluoromethanesulfonate, which suggested the formation of isoquinolinium intermediate in the present direct addition reaction.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 485 - 505
Published online: 21st April, 2008
DOI: 10.3987/COM-08-S(N)34
Enantioselective Synthesis and Proteasome Inhibition of A-Ring Analogs of (-)-Epigallocatechin Gallate (EGCG), the Active Ingredient of Green Tea Extract

Kumi Osanai, Vesna Milacic, Q. Ping Dou, and Tak Hang Chan*

*Department of Chemistry, McGill University, Montreal, Quebec, Canada


The A-ring analog compound 8 of (-)-EGCG (1), the active ingredient of green tea, and compound 9, analog of the natural catechin 6 from C. salvifolius, as well as their enantiomers 10 and 11 have been synthesized enantioselectively. They show proteasomal inhibitory activities under cell free conditions, at a potency lower than that of (-)-EGCG. The results suggest that the hydroxyl groups in A-ring of (-)-EGCG play a role in enhancing the activity. The acetylated derivatives of these compounds, 12-15, show cytotoxic activities and proteasomal inhibition after cellular intake, presumably acting as pro-drugs.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 507 - 514
Published online: 24th April, 2008
DOI: 10.3987/COM-08-S(N)35
Efficient Preparation of 2-Imidazolines from Aldehydes and Ethylenediamines with 1,3-Diiodo-5,5-dimethylhydantoin

Shogo Takahashi and Hideo Togo*

*Graduate School of Science, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba 263-8522 Japan


Various 2-imidazolines were prepared in high yields by reacting aldehydes and ethylenediamines with 1,3-diiodo-5,5-dimethylhydantoin. Moreover, chiral 1,3-bis(imidazolin-2’-yl)benzene and 2,6-bis(imidazolin-2’-yl)pyridines, which function as a chiral ligand, could be directly obtained from corresponding dialdehydes in high yields.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 515 - 520
Published online: 8th April, 2008
DOI: 10.3987/COM-08-S(N)38
Dechalcogenation of Pentachalcogenadistannabicyclo[3.1.1]heptanes

Masaichi Saito,* Hizuru Hashimoto, and Tomoyuki Tajima

*Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Shimo-okubo, Sakura-ku, Saitama-city, Saitama, 338-8570 Japan


Pentathia- and pentaselena-distannabicyclo[3.1.1]heptanes reacted with tributylphosphine to afford tetrathia- and tetraselena- distannabicyclo[2.1.1]hexanes, respectively. The novel heterocyclic framework of a tetrathiadistannabicyclo[2.1.1]hexane was demonstrated by X-ray structural analysis. Structures of a series of pentachalcogena and tetrachalcogena derivatives are discussed.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 521 - 539
Published online: 17th April, 2008
DOI: 10.3987/COM-08-S(N)40
Total Synthesis of Isoindolobenzazepine Alkaloids, Lennoxamine and Chilenine, Based on Palladium-Catalyzed Reduction of Alkenyl Phosphates

Haruhiko Fuwa* and Makoto Sasaki*

*Laboratory of Biostructural Chemistry, Graduate School of Life Sciences, Tohoku University, 1-1 Tsutsumidori-amamiya, Aoba-ku, Sendai 981-8555, Japan


An efficient method for the synthesis of enol ethers and enecarbamates has been developed based on palladium(0)-catalyzed chemoselective reduction of alkenyl phosphates. This method has been applied successfully to the total synthesis of two isoindolobenzazepine alkaloids, lennoxamine and chilenine.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 541 - 550
Published online: 21st April, 2008
DOI: 10.3987/COM-08-S(N)41
Synthesis, Molecular Structure, and Oxidation Behavior of Exhaustively Methylated Azacalix[6]arene

Koichi Ishibashi, Hirohito Tsue,* Hiroki Takahashi, Satoshi Tokita, Kazuhiro Matsui, and Rui Tamura

*Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan


The molecular structure and oxidation behavior of an exhaustively methylated azacalix[6]arene have been investigated with the intention of developing high-spin materials. The azacalix[6]arene adopted a distorted 1,3-alternate conformation in the solid state, whereas the conformation was highly flexible in solution at ambient temperature. As a result of the flexible structure in solution, the decreased stability of the corresponding cation radicals was observed, as compared to that of the smaller inflexible homologue yielding stable cation radicals. Both the conformational inflexibility and the steric protection of reactive sites were found to be crucial for stabilizing the oxidized species of this molecular system.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 551 - 567
Published online: 28th April, 2008
DOI: 10.3987/COM-08-S(N)42
Synthesis of (—)-Talaumidin, a Neurotrophic 2,5-Biaryl-3,4-dimethyltetrahydrofuran Liganan, and Its Stereoisomers

Yoshiyasu Fukuyama,* Kenichi Harada, Tomoyuki Esumi, Daisuke Hojyo, Yumemi Kujime, Naoko Kubo, Miwa Kubo, and Hideaki Hioki

*Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima, 770-8514, Japan


The enantioselective total synthesis of a neurotrophic (-)-talaumidin (1) was achieved in 16 steps from 4-benzyloxy-3-methoxybenzaldehyde in ca. 10.7% overall yield. The synthesis features the construction of the two successive chiral centers C-2 and C-3 by Evans asymmetric anti-aldol protocol as well as of the two chiral centers C-4 and C-5 in a highly stereocontrolled fashion by hydroboration/oxidation and epimerization, followed by Friedel-Crafts arylation. Its stereoisomers (2S,3S,4S,5R)-1a and (2S,3S,4R,5S)-1b were also synthesized from a key intermediate 10 with the 2S and 3S configurations.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 569 - 581
Published online: 21st April, 2008
DOI: 10.3987/COM-08-S(N)45
Stereoselective Synthesis of Pyrrolidin-3-ols from Homoallylamines

Mohamed Medjahdi, José C. González-Gómez, Francisco Foubelo,* and Miguel Yus*

*Department of Organic Chemistry, Faculty of Science, and Institut of Organic Synthesis (ISO), University of Alicante, Apdo. 99, 03080 Alicante, Spain


The reaction of enantiomerically pure N-tert-butylsulfinylhomoallylamines 3 (easily prepared by indium mediated allylation of the corresponding N-tert-butylsulfinylaldimine with allyl bromide) with MCPBA in CH2Cl2 at 25 °C leads to epoxysulfonamide derivatives 4 as a ca. 1:1 mixture of diastereoisomers. Cyclization of compounds 4 under basic conditions (K2CO3 in DMF) affords cis- and trans-pyrrolidin-3-ols 5 and 6, respectively.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 583 - 593
Published online: 8th May, 2008
DOI: 10.3987/COM-08-S(N)46
Structural Aspects of Iodine-Promoted One-Pot Cyclization of O-Bis(methylthio)stilbenes to Thieno[3,2-b]thiophene Derivatives: Synthetic Trials of Tetrathienoacenes from 1,2-Bis(3-methylthiothiophen-2-yl)ethenes

Tatsuya Yamamoto, Eigo Miyazaki, and Kazuo Takimiya*

*Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan


In this paper, attempted reactions for the synthesis of tetrathienoacenes from 1,2-bis(3-methylthiothiophen-2-yl)ethenes by the iodine-promoted one-pot cyclization reaction were described. X-Ray structural analyses of the precursors indicated that the failure of reactions is closely related to the molecular structures around the reaction moiety, in particular, the bond angles defined by the aromatic ring and the neighboring carbon atom in the ethene moiety. We speculate that the larger angles in the 1,2-bis(3-methylthiothiophen-2-yl)ethenes make the intramolecular nucleophilic attack of the methylthio groups to the iodonium intermediate difficult.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 595 - 603
Published online: 24th April, 2008
DOI: 10.3987/COM-08-S(N)47
Simultaneous Formation of Antiparallel β-Sheet-like and Type II β-Turn-like Structures Based on Introduction of Dipeptide Chains with Heterochiral Sequence into Ferrocene Scaffold

Toshiyuki Moriuchi,* Takayoshi Nagai, Takashi Fujiwara, Nami Honda, and Toshikazu Hirao*

*Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Yamada-oka, Suita, Osaka 565-0871, Japan


Simultaneous formation of antiparallel β-sheet-like and type II β-turn-like structures through the intramolecular hydrogen bonds was achieved by the symmetrical introduction of two dipeptide chains with heterochiral sequence (-L-Ala-D-Pro-4APy or -D-Ala-L-Pro-4APy) into the ferrocene scaffold as a central reverse-turn unit. X-ray crystallographic analyses clarified the chirality-organized structure of the ferrocene-peptide bioconjugates, in which the helical chirality of the ferrocene unit was induced. The ferrocene-peptide bioconjugates exhibited an induced circular dichroism (ICD) based on the helical chirality at the absorbance region of the ferrocene moiety.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 605 - 616
Published online: 17th April, 2008
DOI: 10.3987/COM-08-S(N)50
Design, Synthesis and Evaluation of Antitumor and Antiviral Activities of 5-Amino-1H-[1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones (8-Azaguanines) and 7-Amino-1H-[1,2,3]triazolo[4,5-d]pyrimidin-5(4H)-ones (8-Azaisoguanines)

Rafiqul Islam, Noriyuki Ashida, and Tomohisa Nagamatsu*

*Department of Drug Discovery and Development, Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima-naka, Okayama 700-8530, Japan


Preparation of 5-amino-1H-[1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones (5a-h) and 7-amino-1H-[1,2,3]triazolo[4,5-d]pyrimidin-5(4H)-ones (8a-n) was accomplished by nitrosative cyclization of the desired 2,5,6-triaminopyrimidine (2a-h) and 4,5,6-triaminopyrimidine derivatives (7a-n) with nitrous acid, respectively. Compounds 5a-h were also prepared by nucleophilic replacement of the methylthio group of 5-methylthio-1H-[1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-one (4) by appropriate amines. Similarly, some 7-amino derivatives (10a-i) were synthesized by replacement of the thiol groups of the 7-thiol derivative (9) by appropriate amines. Antitumor and antiviral activities of the synthesized compounds were evaluated in vitro.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 617 - 634
Published online: 28th April, 2008
DOI: 10.3987/COM-08-S(N)53
Facile Synthesis of (2-Benzimidazolyl)-1-azaazulenes, (2-Benzothiazolyl)-1-azaazulenes, and Related Compouds and Evaluation of Their Anticancer in vitro Activity

Noriko Yamauchi, Hiroyuki Fujii, Akikazu Kakehi, Motoo Shiro, Masaki Kurosawa, Takeo Konakahara, and Noritaka Abe*

*Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Yamaguchi 753-8512, Japan


Facile syntheses of 2-, 3,- and 8-(2-benzimidazolyl)-1-azaazulenes (2a-c, 5, 7, 9) and 2-, 3-, and 8-(2-benzothiazolyl)-1-azaazulenes (13b-c, 16, 17, 18) were achieved by the condensation of corresponding 1-azaaazulene- carbaldehydes with o-phenylenediamine and 2-aminothiophenol in alcoholic solvents at rt or under reflux under airobic conditions. Reaction of 1-azaazulenecarbaldehyds with 2-aminophenol gave Schiff’s bases (10a-c, 11, 12). Reaction of 2-chloro-1-azaazulene-3-carbaldehyde (1a) with 2-amino- thiophenol in refluxing 1-BuOH gave benzothiazapine-fused 1-azaazulene (20). Reaction of 4-amino-3-mercapto-4H-1,2,4-triazoles (21a-d) with in refluxing 1-BuOH gave triazolothiadizapine-fused 1-azaazulene (22a-d). The structure of trifluolomethyl derivative (22c) was determined by X-ray structure analysis. 3-(2-Benzimidazolyl)-2-chloro-1-azaazulene (2a) showed anticancer activity against HeLa S3 cells (IC50: 5.3 μM).

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 635 - 644
Published online: 24th April, 2008
DOI: 10.3987/COM-08-S(N)54
An Efficient Synthetic Route for a Versatile Ciliapterin Derivative and the First Ciliapterin D-Mannoside Synthesis

Tadashi Hanaya,* Hiroki Baba, Mitsunori Kanemoto, and Hiroshi Yamamoto

*Department of Chemistry, Faculty of Science, Okayama University, Tsushima- naka, Okayama 700-8530, Japan


The key precursor, N2-(N,N-dimethylaminomethylene)-1’-O-(4-methoxybenzyl)-3-[2-(4-nitrophenyl)ethyl]ciliapterin (15) was efficiently prepared from D-xylose via an improved route. The first synthesis of 2’-O-(α-D-mannopyranosyl)ciliapterin (2c) was achieved by treatment of 15 with 2,3,4,6-tetra-O-benzoyl-α-D-mannnopyranosyl bromide in the presence of silver triflate and tetramethylurea, followed by removal of the protecting groups.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 645 - 655
Published online: 28th April, 2008
DOI: 10.3987/COM-08-S(N)56
Development of Tightly Convoluted Polymeric Phosphotungstate Catalysts and Their Application to an Oxidative Cyclization of Alkenols and Alkenoic Acids

Yoichi M. A. Yamada, Haiquin Guo, and Yasuhiro Uozumi*

*Institute for Molecular Science (IMS), Myodaiji, Okazaki, Aichi 444-8787, Japan; ‡RIKEN, Hirosawa, Wako, Saitama 351-0105, Japan


Tightly convoluted polymeric phosphotungstate catalysts were prepared via ionic-assembly of H3PW12O40 and poly(alkylpyridinium)s. An oxidative cyclization of various alkenols and alkenoic acids was efficiently promoted by the polymeric phosphotungstate catalyst in aq. H2O2 in the absence of organic solvents to afford the corresponding cyclic ethers and lactones in high yield. The catalyst was reused four times without loss of catalytic activity. The polymeric phosphotungstate was unambiguously characterized by spectro- and microscopic studies (MAS 31P{1H} NMR, IR spectroscopy, elemental analysis, TEM, SEM, and EDS).

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 657 - 665
Published online: 24th April, 2008
DOI: 10.3987/COM-08-S(N)58
Selective Synthesis of Cyclic Phosphoric Acid Diesters through Oxorhenium(VII)-Catalyzed Dehydrative Condensation of Phosphoric Acid with Alcohols

Akira Sakakura, Masayuki Sakuma, Mikimoto Katsukawa, and Kazuaki Ishihara*

*Graduate School of Engineering, Nagoya University, Chikusa, Nagoya, 464-8603 Japan


The selective synthesis of phosphoric acid diesters has been achieved through the direct catalytic dehydrative condensation of phosphoric acid with two equivalents of alcohols. The present method works especially well for the synthesis of cyclic phosphoric acid diesters. The combination of perrhenic acid and N-methylbenzylamine efficiently catalyzes the dehydrative condensation of phosphoric acid with equimolar amounts of diols to give cyclic phosphoric acid diesters in excellent yields.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 667 - 678
Published online: 1st May, 2008
DOI: 10.3987/COM-08-S(N)60
Preparation of 1,3,3a,7a-Tetrahydroisothianaphthene and Its Application to Tetrahydrothiophene-Fused Porphyrin

Yukiko Katsuyama, Eita Yoshida, Hiroki Uoyama, Noboru Ono, and Hidemitsu Uno*

*Division of Synthesis and Analysis, Department of Molecular Science, Integrated Center for Sciences, Ehime University, Matsuyama 790-8577, Japan


Dehydrobromination of 5,6-dibromoperhydroisothianaphthene with DBU gave a mixture of 1,3,3a,7a-tetrahydroisothianaphthene and 1,3,3a,4-tetrahydroisothianaphthene in a ratio of 5:1. The former compound acted as an s-cis diene in the Diels-Alder reaction with bis(phenylsulfonyl)ethylene to give an adduct, which was successively converted to tetrahydrothiphene-fused pyrroles and porphyrins.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 679 - 688
Published online: 24th April, 2008
DOI: 10.3987/COM-08-S(N)65
2-Alkylidene-1,3-dithiane Monoxides as Activated Alkenes in Rhodium-Catalyzed Addition Reaction of Arylboronic Acids

Suguru Yoshida, Hideki Yorimitsu,* and Koichiro Oshima*

*Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan


2-Methylene-1,3-dithiane 1-oxide reacts with arylboronic acids in the presence of a rhodium catalyst in aqueous dioxane to afford 2-arylmethyl-1,3-dithiane 1-oxides in good yields.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 689 - 698
Published online: 12th May, 2008
DOI: 10.3987/COM-08-S(N)66
Synthesis of 2,5-Diaminopyrazine Derivatives via Dimerization of 2H-Azirin-3-amines

Maged K. G. Mekhael, Anthony Linden, and Heinz Heimgartner*

*University of Zürich, Institute of Organic Chemistry, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland


The 2-monosubstituted 2H-azirin-3-amine (5c) was prepared conveniently by subsequent treatment of N-methyl-N-phenylpropanamide in THF with LDA, diphenyl phosphorochloridate (DPPCl), and sodium azide in DMF. In the absence of nucleophiles, the reaction of 5c in THF with BF3·OEt2 at -78°C yields 2,5-dihydro-2,5-dimethyl-3,6-bis(N-methyl-N-phenylamino)pyrazinium tetrafluoroborate (11). Treatment of the latter with NaOH yields the corresponding 2,5-dihydropyrazine derivative (12), whereas dehydrogenation with DDQ leads to 2,5-dimethyl-3,6-bis(N-methyl-N-phenylamino)pyrazine (13). The structures of 12 and 13 were established by X-ray crystallography.

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Paper | Special issue | Vol 76, No. 1, 2008, pp. 699 - 713
Published online: 21st April, 2008
DOI: 10.3987/COM-08-S(N)67
Total Synthesis of an Endothelin Converting Enzyme Inhibitor, TMC-66

Seijiro Hosokawa,* Hitoshi Fumiyama, Hisato Fukuda, Tomohiro Fukuda, Masashi Seki, and Kuniaki Tatsuta*

*Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan


The first total synthesis and structural determination of TMC-66, an ECE inhibitor, was achieved in short steps by efficient construction of two tricyclic segments and coupling reactions. The oxidative coupling with phenols attaching to electron-withdrawing groups was realized with a novel copper (II) reagent.

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