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
Isao Kuwajima's Special Issues, Vol. 90, No. 2, 2015
Published online: 28th August, 2014
■ Stereoselective Construction of 1β-Azide- and 1β-Cyano-2-deoxyribose Derivatives
Hiromichi Fujioka,* Takahiro Moriya, Kazuhisa Okamoto, Yutaka Minamitsuji, Yoshifumi Ueyama, Nao Matsumoto, and Kenichi Murai
*Graduate School of Pharmaceutical Science, Osaka University, 1-6 Yamadaoka, Suita, Osaka 560-0871, Japan
Abstract
A new method has been developed for the β-selective introduction of azido and cyano groups at the anomeric position of 2-deoxyribose derivatives. This method proceeds via the formation of a collidinium salt intermediate and allows for the stereoselective construction of 1β-azido- and 1β-cyano-2-deoxy-D-ribose derivatives. 2-Deoxy-D-ribose compounds bearing an acetoxy or tert-butoxycarbonyloxy group at their anomeric position performed well as starting materials for the formation of the corresponding 1β-azide and 1β-cyanide derivatives, respectively. 1H NMR studies of the salt intermediates revealed that the nucleophilic substitution reaction of the salt intermediates proceeded in a SN2-fashion.
Published online: 19th August, 2014
■ 4,8-Dihydropyrrol[3,4-f]isoindole as a Useful Building Block for Near-Infrared Dyes
Hidemitsu Uno,* Mitsunori Nakamura, Kazuki Jodai, Shigeki Mori, and Tetsuo Okujima
*Department of Chemistry and Biology, Graduate School or Science and Engineering, Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan
Abstract
4,8-Dihydropyrrol[3,4-f]isoindole was prepared from 4,7-dihydroisoindole based on the modified Barton-Zard reaction. Addition of phenylsulfenyl chloride followed by oxidation and dehydrochlorination gave phenylsulfonyldihydroisoindole, which underwent the smooth reaction with an isocyanoacetate under basic conditions to give 4,8-dihydropyrrol[3,4-f]isoindole-1,5- and 1,7-dicarboxylates in good yields. The pyrrolisoindole was successfully converted to the benzene-fused bisBODIPY, absorption maximum of which was 758 nm.
Published online: 11th September, 2014
■ Synthesis of Pyrrolidinofullerenes via Single Electron Transfer Reaction of Aryldienamines with C60
Naohiko Ikuma,* Hiroyuki Yamamoto, Ken Kokubo, and Takumi Oshima
*Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
Abstract
Variously aryl-substituted pyrrolidinofullerenes were synthesized via a single electron transfer (SET) reaction of diaryldienamines with C60 and the following consecutive 1,6-hydrogen shift and the [3 + 2] cycloaddition of the generated radical ion pair. The LUMO levels of pyrrolidinofullerenes were ca. 0.1 eV higher than C60, consequently suppressing the bisadduct formation. The phenyl –substituted pyrrolidinofullerene 2a representatively exhibited the protic acid-catalyzed intramolecular Friedel–Crafts cyclization and the DDQ induced oxidative reversion into C60.
Published online: 20th August, 2014
■ Total Synthesis of Maremycins A and D1 Using Chiral and Cyclic Nitrone with (E)-3-Ethylidene-1-methylindolin-2-one
Tohru Ueda, Mitsuhide Inada, Nobuyoshi Morita, and Osamu Tamura*
*Laboratory of Organic Chemistry, Pharmaceutical Sciences, Showa Pharmaceutical University, 3-3165, Higashi-tamagawagakuen, Machida, Tokyo 194-8543, Japan
Abstract
Total syntheses of maremycin A (4) and maremycin D1 (8) were described, featuring 1,3-dipolar cycloaddition of a chiral cyclic nitrone 15 with (E)-3-ethylidene-1-methylindolin-2-one (13). The cycloaddition was reversible, especially at high temperature in the presence of a Lewis acid or in a solvent possessing a high acceptor number. One of the cycloadducts was efficiently led to maremycin A (4) and maremycin D1 (8). High optical purity of 4 was confirmed by chiral HPLC comparison with ent-4 prepared from ent-15 and 13.
Published online: 23rd October, 2014
■ Lithium tert-Butoxide-Mediated Carboxylation Reactions of Unprotected Indoles and Pyrroles with Carbon Dioxide
Woo-Jin Yoo, Thanh V. Q. Nguyen, Montse Guiteras Capdevila, and Shū Kobayashi*
*Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
Abstract
Unprotected indoles and pyrroles were found to undergo base-mediated carboxylation reactions under ambient pressure of carbon dioxide. It was found that this transition metal-free carboxylation reaction proceeded smoothly with the use of a large excess of LiOtBu.
Published online: 5th September, 2014
■ Thiazole/Thiazolone-Fused Cycloheptatrienyl Phosphonates: Reactions of 2H-Cyclohepta[d]thiazole-2-thione and -2-one with Phosphites
Ohki Sato* and Ikumi Suzuki
*Department of Chemistry, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570 , Japan
Abstract
2H-Cyclohepta[d]thiazole-2-thione reacted with either trimethyl or dimethyl phosphite to furnish dimethyl 2-methylthio-4H-cyclohepta[d]thiazole-4-phosphonate and the regioisomers, 6- and 8-phosphonates. In the reaction with triphenyl phosphite, the successive S-methylation by methyl iodide and hydrolysis afforded an isomeric mixture of diphenyl 4-, 6- and 8-phosponates. Treatment of the oxygen analogue, 2H-cyclohepta[d]thiazol-2-one and triphenyl/diphenyl phosphite with/without hydrolysis gave diphenyl 3,4-dihydro-2H-cyclohepta[d]thiazol-2-one-4-phosphonate and the isomeric 6- and 8-phosphonates.
Published online: 27th August, 2014
■ Synthesis, Properties and Crystal Structures of 2,7,12,17-Tetraarylporphycenes
Daiki Kuzuhara,* Haruka Nakaoka, Takuya Okabe, Naoki Aratani, and Hiroko Yamada*
*Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
Abstract
We have synthesized 2,7,12,17-tetraarylporphycenes, which have phenyl (7a), p-trifluoromethylphenyl (7b) or p-methoxyphenyl (7c) groups, by McMurry coupling. The crystal structures revealed that 7a formed a herringbone-type arrangement, while 7b formed a slip-stacked structure with π-π stacking. The reduction potentials of these porphycenes depend on the attached aryl groups: –1.02 V (vs. ferrocene/ferrocenium cation) for 7b (Ar = p-C6H4CF3), –1.17 V for 7a (Ar = Ph) and –1.23 V for 7c (Ar = p-C6H4OMe), which are close to that of PC61BM (Ered = –1.08 V). These porphycenes, thus, are expected to behave as n-type semiconducting materials in OTFT and OPV devices.
Published online: 29th October, 2014
■ Efficient Desulfinative Cross-Coupling of Heteroaromatic Sulfinates with Aryl Triflate in Environmentally Friendly Protic Solvents
Daniel Mangel, Cindy Buonomano, Stéphane Sévigny, Gianna Di Censo, Gowsic Thevendran, and Pat Forgione*
*Department of Chemistry and Biochemistry, Concordia University, 7141 Sherbrooke Street West, SP 201.00, Montreal, Quebec, H4B 1R6, Canada
Abstract
Aryl-substituted heteroaromatics were synthesized via desulfinative cross-coupling reactions using aryl triflate and heteroaromatic sulfinate coupling partners. This method uses synthetically versatile aryl triflates to access aryl-substituted heteroaromatics in good yields employing aqueous and alcoholic media without the use of base, additives or co-catalysts.
Published online: 18th September, 2014
■ Toward the Pluramycins: Route Exploration from Dihydroxyanthrone Tricyclic Platform to an Aglycon, Saptomycinone B
Kei Kitamura, Yoshio Ando, Yoshihiko Maezawa, Takashi Matsumoto,* and Keisuke Suzuki*
*Depatrtment of Chemistry, Tokyo Institute of Technology, 2-12-1,Oh-Okayama, Meguro-ku, Tokyo 152-8552, Japan
Abstract
In connection with the total synthesis of the pluramycin-class antibiotics, we recently found dihydroxyanthrone derivatives to be suitable platforms for the installation of bis-C-glycosides. As a basis for the total synthesis, we explored viable routes to construct the characteristic tetracyclic skeleton. By setting saptomycinone B (5) as a model target, anthrone 6 was combined with the side chain moiety to access key intermediate 9, from which two viable routes have been developed. One of the routes has been exploited in the realization of our recent total synthesis of saptomycin B (4).
Published online: 12th September, 2014
■ Synthesis of the C1-C7 and C8-C18 Segments of ent-Amphidinin A
Haruaki Ishiyama, Masahiro Hangyou, Ayumi Nakatsu, Yuta Mori, and Jun'ichi Kobayashi*
*Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan
Abstract
A stereoselective synthesis of the C1-C7 and C8-C18 segments of the enantiomer of amphidinin A, a cytotoxic polyketide from the culture cells of a symbiotic marine dinoflagellate Amphidinium sp. (strain Y-5), has been achieved, utilizing sulfone-aldehyde coupling, Sharpless asymmetric dihydroxylation, Katsuki-Sharpless asymmetric epoxidation, and Julia-Kocienski olefination.
Published online: 22nd September, 2014
■ Synthesis and Preliminary Biological Evaluation of 2-[3-(Tetrazolyl)propyl]-1α,25-dihydroxy-19-norvitamin D3
Masashi Takano, Erika Higuchi, Kazunari Higashi, Keisuke Hirano, Akiko Takeuchi, Daisuke Sawada, and Atsushi Kittaka*
*Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
Abstract
Four new 19-norvitamin D3 analogs, 2α-[3-(tetrazol-1-yl)propyl]-, 2β-[3-(tetrazol-1-yl)propyl]-, 2α-[3-(tetrazol-2-yl)propyl]-, and 2β-[3-(tetrazol-2-yl)propyl]-1α,25-dihydroxy-19-norvitamin D3 were synthesized. Among them, 2α-[3-(tetrazol-1-yl)propyl]-1α,25-dihydroxy-19-norvitamin D3 showed weak binding affinity for vitamin D receptor (VDR) (2.6% of 1α,25-dihydroxyvitamin D3: ca. 15% of 1α,25-dihydroxy-19-norvitamin D3) and weak VDR transactivation activity in human osteosarcoma cells, which was determined by luciferase assays (EC50 7.3 nM, when 1α,25-dihydroxyvitamin D3 0.23 nM). Although the other three compounds could not act as VDR binders by evaluation of the competition assays, 2α-[3-(tetrazol-2-yl)propyl] analog showed weak transactivation activity (EC50 12.5 nM).
Published online: 13th August, 2014
■ New Approach to Cyclophanes Containing Ethyleneoxy Bridge by Glaser–Eglinton Coupling
Sambasivarao Kotha* and Gopalkrushna T. Waghule
*Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai - 400076, India
Abstract
Three strategies have been explored to generate cyclophane derivatives. In this regard, we identified alkyne metathesis, Diels–Alder reaction, and Glaser–Eglinton coupling as key steps. To this end, cyclophane derivatives containing ethyleneoxy bridge were successfully synthesized in four steps involving Glaser–Eglinton coupling and catalytic hydrogenation sequence.
Published online: 5th August, 2014
■ Stereochemistry of Vinylogous Rubottom Oxidation of Proline-Fused Cyclohexadienol Silyl Ether
Kentaro Okano, Shun Okaya, Taichi Kurogi, Hideto Fujiwara, and Hidetoshi Tokuyama*
*Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
Abstract
The steric effect of vinylogous Rubottom oxidation of proline-fused cyclohexadienol silyl ether was investigated. The facial selectivity in the oxidation is governed by a synergistic effect of the proximal ester and a protective group on the nitrogen.
Published online: 5th August, 2014
■ Synthesis of Rhodotorulic Acid and Its 1,4-Dimethylated Derivative
Michiyasu Nakao, Shintaro Fukayama, Syuji Kitaike, and Shigeki Sano*
*Molecular Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokushima, 1-78 Sho-machi, Tokushima 770-8505, Japan
Abstract
Facile syntheses of rhodotorulic acid, isolated from Rhodotorula pilimanae as a siderophore, and its 1,4-dimethylated derivative have been achieved by microwave-assisted cyclization of the corresponding dipeptide precursors.
Published online: 4th August, 2014
■ Isolation of Alkamides with Death Receptor-Enhancing Activities from Piper chaba
Hoque Tahmina, Kazufumi Toume, Midori A. Arai, Samir K. Sadhu, Firoj Ahmed, and Masami Ishibashi*
*Department of Natural Products Chemistry, Graduate School of Pharmaceutical Science, Chiba University, 1-8-1 Inohana, Chuo, Chiba, Japan
Abstract
In the screening program for natural bioactive compounds that enhance the expression of death receptor 5 (DR5), activity-guided fractionation of the Piper chaba (Piperaceae) root MeOH extract led to the isolation of four alkamides (1-4). Compounds 1, 3, and 4 enhanced DR5 promoter activity while pellitorine (3) exhibited TRAIL-resistance-overcoming activity.
Published online: 10th October, 2014
■ Palladium Catalyzed Intramolecular Vinylselenation and Vinylthiolation of Allenes
Susumu Tsuda, Maiko Okuyama, Shin-ichi Fujiwara,* Takanori Iwasaki, Hitoshi Kuniyasu, and Nobuaki Kambe*
*Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
Abstract
Intramolecular vinylselenation of allenes 1a,b proceeds in the presence of Pd(0) catalyst producing pyridin-2-one derivatives 2a,b having a high degree of unsaturation as a sole product. This cyclization could also be applied to vinylthiolation and to the construction of seven-membered lactams.
Published online: 19th August, 2014
■ Palladium-Mediated Intramolecular Biaryl Coupling Reaction: Convenient Preparation of Furoquinolinone Derivatives
Hitoshi Abe,* Mayu Kamimura, Yoshinori Komatsu, and Yoshikazu Horino
*Department of Environmental Applied Chemistry, Faculty of Engineering, Toyama University, Gofuku 3190, Toyama 930-8555, Japan
Abstract
Furo[2,3-c] or furo[3,2-c]quinolinone derivatives were prepared via the intramolecular biaryl coupling reaction of 2-furoylanilides or 3-furoylanilides using a palladium catalyst.
Published online: 6th August, 2014
■ Synthetic Studies toward Welwitindolinone Alkaloids. Tandem Aldol–Michael Reaction to Form the Carbocyclic Core of Welwitindolinones
Masato Shima and Masahiro Toyota*
*Team TOYOTA, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 593-8531, Japan
Abstract
A tandem aldol ̶Michael reaction effectively constructed a bridged ketone, which is the carbocyclic core of the welwitindolinone family.
Published online: 26th September, 2014
■ Marine Natural Occurring 2,5-Diketopiperazines: Isolation, Synthesis and Optical Properties
Rémi Laville, Thanh Binh Nguyen, Céline Moriou, Sylvain Petek, Cécile Debitus, and Ali Al-Mourabit*
*Department of Chemistry, Institut de Chimie des Substances Naturelles, CNRS, 1, Avenue de la Terrasse, 91190 Gif-sur-Yvette, France
Abstract
Seven 2,5-diketopiperazines (DKPs) were isolated from the Fijian marine sponge Acanthella cavernosa. NMR and circular dichroism (CD) comparison with synthetic L-L DKPs allowed us to determine unambiguously the L-L absolute configuration of the natural DKPs. This work initiated the setting up of an optical properties database of natural DKPs, including specific rotation and CD.
Published online: 3rd October, 2014
■ Natural-Product-Based Insecticidal Agents 16. Semisynthesis of C7-Oxime Sulfonate Ester Derivatives of Obacunone as Insecticidal Agents against Mythimna separata Walker
Xiang Yu, Guodong Ding, Zhinan Gao, Jing Zha, and Hui Xu*
*Laboratory of Pharmaceutical Design & Synthesis, College of Life Sciences, Northwest A & F University, Xinong Road 22#, Yangling, Shaanxi, 712100, China
Abstract
A series of novel C7-oxime sulfonate ester derivatives of obacunone (3a-f) were synthesized. Their insecticidal activity was also evaluated at the concentration of 1 mg/mL against the pre-third-instar larvae of oriental armyworm (Mythimna separata Walker), a typical lepidopteran pest. Especially C7-oxime p-ethylphenylsulfonate ester of obacunone (3d) exhibited more potent insecticidal activity than their precursor obacunone and toosendanin (a positive control).
Published online: 27th August, 2014
■ Synthesis of Unsymmetrical, gem-Disubstituted Bisamides
Gabriel Schäfer, Lukas Leu, and Jeffrey W. Bode*
*Laboratory of Organic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zuerich, Switzerland
Abstract
The addition of Grignard reagents to isocyanates allowed for the first successful synthesis of ketone-derived unsymmetrical, gem-disubstituted bisamides. The key to success was the in situ generation of the isocyanates under mild reaction conditions via Lossen rearrangement from the corresponding hydroxamic acids.
Published online: 20th August, 2014
■ A Concise Approach to Tetracyclic Spiroamine Scaffold of Erythrinan Alkaloids via an Oxidative Dearomatization-Spirocyclization Sequence
Emi Saito, Akihiko Nakamura, and Masahisa Nakada*
*Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
Abstract
This paper describes a novel synthetic approach to 11,12-dimethoxy-8,9-dihydro-1H-indolo[7a,1-a]isoquinoline-2,6-dione, which is a key synthetic intermediate to some erythrinan alkaloids. This concise approach features an oxidative dearomatization-spirocyclization sequence mediated by phenyliodine (III) bis(trifluoroacetate) (PIFA) that efficiently forms the tetracyclic spiroamine scaffold. An unusual solvent effect in the oxidative dearomatization-spirocyclization sequence is also described.
Published online: 8th September, 2014
■ Synthesis of Intermediary P3 Phosphazenium Framework and Its Derivatization to Chiral Cationic Macrocycles Including Two P3 Phosphazenium Units with Hydrogen Bond Donor Sites
Masahiro Terada,* Kengo Goto, Takashi Ikehara, and Azusa Kondoh
*Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, sendai 980-8578, Japan
Abstract
A new synthetic route to key intermediary phosphonium possessing a P3 phosphazene framework was developed. The reaction of the obtained intermediary phosphonium with chiral diamine, (1S,2S)-1,2-diphenyl-1,2-ethanediamine, resulted in the formation of 18-membered macrocyclic bisphosphazenium, the structure of which was verified by single-crystal X-ray diffraction analysis. The macrocyclic bisphosphazenium showed potential application as a chiral anion receptor and a chiral template in asymmetric catalysis.
Published online: 11th September, 2014
■ Solution-Phase-Peptide Synthesis without Purification of Column Chromatography and Recrystallization by Protecting Amino Acid Esters with Phosphinyl Chloride
Guanghui An, Wei Zhou, Xiaokang Xu, Yi Pan, and Guigen Li*
*Department of Chemistry & Biochemistry, Texas Tech University, Lubbock, TX 79409-1061, U.S.A.
Abstract
Biphenyl phosphinyl chloride (Bpp-Cl) has been successfully applied for the amino acid GAP (Group-Assisted Purification) protection. The resulting N-protected amino acid esters have been readily converted into the corresponding amino acids and peptides through GAP operation. Biphalin, enkephalin derivatives and the fragments of surfaxin have also been synthesized via GAP work-up by avoiding column chromatography. The GAP protecting group (Bpp) can be recovered and can implement the former phosphonyl groups in peptide synthesis.
Published online: 14th October, 2014
■ Stereoselective Aza-Henry Reaction of Chiral tert-Butanesulfinyl Imines with Methyl or Ethyl 4-Nitrobutanoate: Easy Access to Enantioenriched 6-Substituted Piperidine-2,5-diones
M. Jesús García-Muñoz, Francisco Foubelo,* and Miguel Yus*
*Department of Organic Chemistry, Faculty of Sciences and Institute of Organic Synthesis (ISO), University of Alicante, P.O. Box 99, 03080 Alicante, Spain
Abstract
The base-catalyzed addition of 4-nitrobutanoates 6 to N-tert-butanesulfinyl imines 8 under solvent-free reaction conditions proceeded with high face diastereoselectivity. The resulting β-nitroamine derivatives 9 were easily transformed into 6-substituted piperidine-2,5-diones 11 upon removal of the sulfinyl group with concomitant δ-lactam formation and functional group transformation under Nef reaction conditions.