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Published online: 29th August, 2014

Paper | Regular issue | Prepress
DOI: 10.3987/COM-14-13070
Efficient Syntheses of Fluorine-containing Pyrimido[5,4-c]quinolines and Benzo[h][1,6]naphthyridines by Condensation Reactions of 3-Trifluoro-acetylquinolin-4-amine with Aldehydes and Ketones

Etsuji Okada,* Mizuki Hatakenaka, Shiro Nakano, Takushi Sakaemura, Takashi Mori, and Terukazu Terauchi

*Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan

Abstract

3-Trifluoroacetylquinolin-4-amine reacted easily with various aldehydes in the presence of aqueous ammonia to afford mainly trifluoromethylated pyrimido[5,4-c]quinoline derivatives in moderate to high yields. In contrast, the use of ketones instead of aldehydes under almost the same conditions, mostly gave benzo[h][1,6]naphthyridine derivatives in excellent combined yields.

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Published online: 28th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)86
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.

PDF (676KB)

Published online: 27th August, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)58
Removal of Xylylene Groups from Tetrakis(o-xylylenedithio)phthalocyanines with Toluene/Aluminum Chloride and Construction of Dithiaphosphole Rings

Takeshi Kimura* and Shiduko Nakajo

*Center for Instrumental Analysis, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan

Abstract

Xylylene groups were removed from tetrakis(o-xylylenedithio)phthalocyanines via C-S bond cleavage by treatment with toluene and aluminum chloride. Octathiolate anions generated were reacted with dichlorophenylphosphine to produce phthalocyanines with four dithiaphosphole rings. The structures of the products were determined by NMR and FABMS. Electrochemical and optical properties of them were verified by cyclic voltammetry and UV-vis spectroscopy.

PDF (385KB)

Published online: 27th August, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)89
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.

PDF (514KB)

Published online: 27th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)101
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.

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Published online: 25th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)52
Preparation of (2R,4S)/(2S,4S)-4-Hydroxypipecolinic Acid Derivatives from L-(–)-Malic Acid

Shuqiang Yin, Hiroshi Taneda, Bozhi Li, Dejun Zhou, Daishiro Minato, Kenji Sugimoto, and Yuji Matsuya*

*Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan

Abstract

Synthetically important 4-hydroxypipecolinic acid derivatives were efficiently prepared from commercially available L-(–)-malic acid. The stereochemistries of the derivatives synthesized by our method were determined by coupling constant analyses with key methine protons on C2 and C4.

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Published online: 21st August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)78
[2+2+2] Cycloaddition of Sulfanylbenzene-Tethered Diynes with Alkynes for the Synthesis of Multi-Substituted Dibenzothiophene Derivatives

Yu-ki Tahara, Riku Matsubara, and Takanori Shibata*

*Chemistry and Biochemistry, Advanced Research Center of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan

Abstract

An intermolecular [2+2+2] cycloaddition of sulfanyl- and sulfonylbenzene-tethered 1,6-diynes with alkynes using rhodium catalysts gave dibenzothiophene derivatives in moderate to excellent yields. The consecutive reaction of tetraynes with an alkyne gave an axially chiral 1,1’-bi(dibenzothiophenyl) and its tetraoxide with up to excellent ee.

Supporting Info. (1.4MB)PDF (553KB)

Published online: 21st August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)71
Macrobicyclic and Macrotricyclic Derivatives of N,N’,N’’,N’’’-Tetrasubstituted Cyclen and Cyclam

Sergei M. Kobelev, Alexei D. Averin, Alexei K. Buryak, Andrei I. Vovk, Valerii P. Kukhar, Franck Denat, Roger Guilard, and Irina P. Beletskaya*

*Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991, Moscow, Russia

Abstract

N,N’N’’,N’’’-Tetrabenzyl derivatives of cyclen and cyclam possessing two bromine atoms in trans-positioned phenyl rings were introduced in the Pd-catalyzed amination reactions with oxadiamines and polyamines to provide a wide series of macrobicyclic compounds with tetrabenzyl substituted cyclen and cyclam central moieties in yields up to 31%. Macrocycles based on 1,7-dibenzylcyclen were modified with two 3-bromobenzyl substituents and introduced in the Pd-catalyzed macrocyclization with di- and trioxadiamines to afford spherically shaped macrotricyclic cryptands in yields up to 33%. An alternative approach to isomeric macrotricyclic cryptands employed Pd-catalyzed amination of di(Boc)-di(3-bromobenzyl)cyclen followed by the dialkylation of the resulting bicycle with two bromobenzyl groups and final catalytic macrocyclization step (yields up to 24%).

PDF (722KB)

Published online: 20th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)47
Synthesis and Biological Evaluation of C-Aromataxane Derivatives as P-Glycoprotein-mediated Multi Drug Resistance Reversal Agents

Takayuki Doi,* Naoko Yamaguchi, Kosuke Ohsawa, Kazuoki Nakai, Masahito Yoshida, Kazuhiro Satake, Yuji Mitani, Hiroshi Nakagawa, Takashi Takahashi, and Toshihisa Ishikawa

*Graduate School of Pharmaceutical Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan

Abstract

Synthesis and evaluation of C-aromataxane derivatives as P-glycoprotein-mediated MDR reversal agents have been demonstrated. Several derivatives possessing N-benzoylphenylisoserine at the C2 or C14 position of the template 2a were readily synthesized and were evaluated their affinity for P-glycoprotein. Most of the synthesized derivatives exhibited much lower cytotoxicity in both KB-3-1 cells and MDR KB-G2-cells than paclitaxel (1), and it should be noted that the compound (14R)-5a exhibited high Km and Vmax/Km values, and cytotoxicity of paclitaxel (1) in MDR KB-G2 cells was significantly recovered (98% reduction, IC50 30 nM) in the presence of 5a (5.0 μM). The structural features such as endo-cage conformation and the stereochemistry at the C14 position is crucial to exhibit an excellent affinity for P-glycoprotein.

Supporting Info. (395KB)PDF (874KB)

Published online: 20th August, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)95
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.

PDF (318KB)

Published online: 20th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)93
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.

PDF (790KB)

Published online: 19th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)43
Synthesis of Bicyclic Dioxetanes bearing a Hydroxyphenanthrene or Hydroxy[4]helicene Moiety and Their Base-induced Chemiluminescent Decomposition

Yohei Koyama, Nobuko Watanabe, Hisako K. Ijuin, and Masakatsu Matsumoto*

*Department of Chemistry, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan

Abstract

Six bicyclic dioxetanes bearing a 1-hydroxyphenanthren-3-yl 2-iv, 3-hydroxyphenanthren-1-yl 2-ov, 4-hydroxyphenanthren-2-yl 2-oh, 2-hydroxyphenanthren-4-yl 2-ih, 4-hydroxy[4]helicen-2-yl 3-iv and 2-hydroxy[4]helicen-4-yl group 3-ov were synthesized and their base-induced chemiluminescent decomposition was investigated in a TBAF (tetrabutylammonium fluoride) / MeCN system. For dioxetanes in the iv-series 2-iv and 3-iv including α-naphthol-analog 17a and those in the ov-series 2-ov and 3-ov including β-naphthol-analog 17b, we investigated how the chemiluminescence properties changed with an increase in the number of fused benzene rings of a hydroxyarene moiety attached to a dioxetane ring. The results showed that a) maximum wavelength of chemiluminescence λmaxCL tended to shift to a longer wavelength region as the number of fused benzene rings increased, b) the kCTID values for the iv-series were >1000 times larger than those for the ov-series regardless of the number of fused benzene rings, and c) a dioxetane in the iv-series tended to have a higher singlet-chemiexcitation efficiency ΦS than the corresponding dioxetane in the ov-series. This tendency could be explained by the “syn/anti” rotational isomerism of an aromatic electron donor, where an anti-rotamer gives ΦS far more effectively than a syn-rotamer.

Supporting Info. (3MB)PDF (713KB)

Published online: 19th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)91
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.

PDF (356KB)

Published online: 19th August, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)84
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.

PDF (267KB)

Published online: 19th August, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)27
Facile Synthesis of Guaiazulene-Heterocycle Hybrids via Ugi Multicomponent Reactions

Naoko Takenaga,* Koh Fukazawa, Miki Maruko, and Koichi Sato*

*Laboratory of Medicinal Chemistry, Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan

Abstract

The Ugi reaction with isocyanoazulene 1 afforded a variety of azulene-heterocycle hybrids. The described approach could be applied to combinatorial synthesis of biologically active compounds of the azulene series.

PDF (308KB)

Published online: 18th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)59
Rhodium-catalyzed 2-Methylthiolation Reaction of Thiazoles/Oxazoles using 2-(Methylthio)thiazole

Mieko Arisawa,* Yuri Nihei, and Masahiko Yamaguchi*

*Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba-ku, sendai 980-8578, Japan

Abstract

RhH(PPh3)4 and 1,3-bis(dicyclohexyl)phosphinopropane (dcypp) catalyze the 2-methylthiolation of oxazoles and thiazoles using 2-(methylthio)thiazole as a thiolating reagent. The methylthio transfer reaction is under equilibrium, and various 2-methylthiolated thiazoles and oxazoles were obtained in moderate to good yields by removing thiazole under refluxing o-dichlorobenzene.

PDF (332KB)

Published online: 15th August, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)72
Facile Preparation of 1,2-Dihydroisoquinolines from N-Benzylsulfonamides and Bromoacetylenes

Masahito Yamagishi, Azusa Ishii, Takeshi Hata, and Hirokazu Urabe*

*Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan

Abstract

Nucleophilic addition of N-benzylsulfonamides to 1-bromo-1-alkynes proceeded in a highly regio- and stereoselective manner to give (Z)-N-benzyl-N-(1-bromo-1-alken-2-yl)sulfonamides. These adducts cyclized via Pd-catalyzed aromatic C-H bond activation to afford 1,2-dihydroisoquinolines in good yields.

Supporting Info. (6.4MB)PDF (510KB)

Published online: 14th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)77
Investigation of Pd(II)-Catalyzed Cyclization of Chiral θ-Hydroxy-α,β,γ,δ-unsaturated Dienol

Akiko Ida, Naoyuki Hoshiya, and Jun'ichi Uenishi*

*Pharmacetuical Chemistry, Kyoto Pharmaceutical University, 1 Shichono-cho, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan

Abstract

PdCl2(MeCN)2 catalyzed intramolecular cyclization of optically pure θ–hydroxyl-α,β,γ,δ−dienylethanols 1 and 2 are described. cis and trans-2- Benzyloxymethyl-6-(1,3-pentadienyl)tetrahydropyrans 3 and 4 were produced stereoselectively with a ratio of 3:1 in excellent yield. No 1,5-chirality transfer was observed in the cyclization reaction.

Supporting Info. (2.6MB)PDF (520KB)

Published online: 13th August, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)90
Synthesis of Macrocyclic Penta- and Tetraoxazoles as G-Quadruplex Ligands

Shadi Sedghi Masoud, Yamato Tsushima, Keisuke Iida, and Kazuo Nagasawa*

*Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, Tokyo 184-8588, Japan

Abstract

The penta- and tetraoxazole telomestatin analogs L2H2-5OTD (4) and L2H2-4OTD (5) were synthesized as new G-quadruplex ligands in order to evaluate the influence of the size of the planar macrocycle on the G-quadruplex-stabilizing efficacy. These ligands were less potent stabilizers of various G-quadruplex-forming oligonucleotides than L2H2-6OTD (2a), which has a hexaoxazole-type macrocycle.

PDF (377KB)

Published online: 13th August, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)37
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.

Supporting Info. (853KB)PDF (328KB)

Published online: 13th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(S)82
Oxidative 1,1’-Coupling of Highly Alkylated 2-Methoxycarbonylazulenes

Ryszard Ostaszewski and Hans-Jürgen Hansen*

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

Abstract

The oxidation of highly alkylated methyl azulene-2-carboxylates 1b1d and a dimethyl azulene-1,2-dicarboxylate 1a with TEMPO (2,2,6,6-tetramethyl-piperidine-1-oxyl) in the presence of Et2O·BF3 ((diethyloxonio)trifluoroborate) in benzene at 5 °C leads in moderate yield to the corresponding 1,1’-biazulene-carboxylates 2a2d (Table 1).

PDF (332KB)

Published online: 8th August, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)53
Diquat Triflate, a Precursor of Organic Reductant

Manabu Kuroboshi,* Takashi Kondo, and Hideo Tanaka

*Division of Chemsitry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan

Abstract

Electroreduction of diquat triflate gave a potent organic reductant, which promoted reductive dimerization of aryl bromides in the presence of palladium catalysts to give the corresponding biaryl compounds.

PDF (442KB)

Published online: 8th August, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)60
Synthesis of α-Halobutenolides using the Nucleophilicity of Magnesium Alkylidene Carbenoids

Tsutomu Kimura,* Kazuki Fukuda, Gaku Kashiwamura, and Tsuyoshi Satoh*

*Tokyo University of Science, Kagurazaka 1-3, Shinjuku-ku, Tokyo 165-0035, Japan

Abstract

α-Halobutenolides were synthesized from halomethyl p-tolyl sulfoxides, α-bromoketones, and phenyl chloroformate in three steps using the nucleophilicity of magnesium alkylidene carbenoids. The reaction of α-bromoketones with [halo(p-tolylsulfinyl)methyl]lithiums and the subsequent basification of the reaction mixture using an aqueous NaOH solution afforded 1-chloro-3-hydroxyprop-1-enyl p-tolyl sulfoxides in 83–99% yield. A phenoxycarbonyl group was then introduced to the hydroxyl group of the sulfoxides by reacting with phenyl chloroformate in the presence of pyridine. The sulfoxide/magnesium exchange reaction of the cyclization precursors with i-PrMgCl•LiCl led to the formation of α-halobutenolides in moderate to good yields.

Supporting Info. (234KB)PDF (362KB)

Published online: 8th August, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)50
The Cycloaddition of 2-Phenylamino-1-azaazulene with Diphenylacetylene using Palladium Catalytic Systems

Hiroyuki Fujii,* Shigeki Oka, Ippei Nakamura, Yu Kawai, Reiko Ikeda, Takeo Konakahara, and Noritaka Abe

*Scientific Research Center, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8512, Japan

Abstract

Selective cycloaddition was achieved by the reaction of 2-phenylamino-1-azaazulene (3) with diphenylacetylene (4) in the presence of Pd catalyst providing N-(1-azaazulen-2-yl)-2,3-diphenylindoles.

PDF (366KB)

Published online: 8th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)49
Perylene-based, Bis(terpyridine)-Ru(II) Complexes: Synthesis, Electrochemical and Photovoltaic Properties

Hany El-Batal, Juan Manríquez Rocha, Perla F. Méndez, Luis A. Godínez, Kai Guo, Xiaopeng Li, Xiaocun Lu, Chrys Wesdemiotis, Charles N. Moorefield, and George R. Newkome*

*Departments of Polymer Science and Chemistry, The University of Akron, Akron, OH 44325-4717, U.S.A.

Abstract

Perylene-based, terpyridine-Ru(II) complexes are synthesized and their electrochemical and photoelectrochemical properties are studied; their fabrication into dye-sensitized solar cells are described (DSSCs) and their resultant photovoltaic properties are evaluated.

Supporting Info. (1MB)PDF (622KB)

Published online: 7th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)51
A New Class of Structurally Simple and Highly Emissive Fluorophores with a Pyridine–Acetylene–Phenol Conjugate

Yuki Ohishi, Hajime Abe,* and Masahiko Inouye*

*Department of Chemical Biology, Graduate School of Pharmaceutical Sciences, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan

Abstract

A model compound for pyridine–acetylene–phenol conjugates was prepared, and its hydrogen-bonding and spectroscopic properties were studied. Pyridine and phenol moieties worked as a hydrogen-bonding acceptor and an donor, respectively, so that the conjugate model efficiently bound to MeOH. The absorption and fluorescence spectra showed remarkable additive effects against acid and base, illustrating the application of the conjugates to recognition-sensitive fluorophores.

Supporting Info. (1.6MB)PDF (1.1MB)

Published online: 7th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)63
Enantiodivergent Synthesis of Wieland-Miescher Ketone Analog Mediated by a Chiral Pyridinylmethylamine Derivative

Shota Honda, Kohei Inomata,* and Yasuyuki Endo*

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

Abstract

A new enantiodivergent route to provide the Wieland-Miescher ketone analog (3b) bearing a 7-membered ring via the intramolecular aldol reaction of the trione (5) mediated by a single chiral pyridinylmethylamine derivative (13e) was established. Although the enantioselectivities of 3b were moderate, the complete inversion of the enantioselectivities was observed based on the amount of additional trifluoroacetic acid (TFA). The basicity of the nitrogen atom on the pyridine ring was very important for this enantiodivergent behavior.

PDF (430KB)

Published online: 6th August, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)85
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.

Supporting Info. (351KB)PDF (328KB)

Published online: 6th August, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)56
Thermal [2+2]-Cycloadditions of Diphenylketene with Aryl- and Hetaryl-substituted Thioketones

Grzegorz Mlostoń,* Katarzyna Urbaniak, Anna Szychowska, Anthony Linden, and Heinz Heimgartner*

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

Abstract

The reaction of diphenylketene (1) with aryl- and hetaryl-substituted thioketones (2) gave the corresponding 3,3,4,4-tetraarylthietan-2-ones (3) in good yields. Remarkably, the reactions with bis-hetaryl-substituted thioketones occurred significantly faster compared with those involving the bis-aryl-substituted thioketones. The structure of compound 3c has been established by X-ray crystallography.

PDF (411KB)

Published online: 6th August, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)55
An Access to the 13-Membered Cyclophane Substructure in GKK1032As: An Intramolecular 1,4-Addition Approach

Satoka Nagai, Yuka Yamagishi, Yuta Shimizu, Ken-ichi Takao, and Kin-ichi Tadano*

*Department of Applied Chemistry, Emeritus, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, Japan

Abstract

The construction of the 13-membered para-cyclophane substructure in GKK1032As, a member of novel pyrrolidinone-containing bioactive natural products, has been explored. An efficient approach for this synthetically formidable object was found, which relied on an intramolecular 1,4-addition between a nitromethylene group and a vinyl ketone moiety both incorporated as side chains into the 6/5/6-tricyclic (the A/B/C-ring system) of the GKK1032s.

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