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Regular & Special Issues

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Published online: 1st October, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)70
Selective Adsorption of Mercury(II) Ion by p-tert-Butylcalix[4]thiacrown-5 at a Solid-Liquid Interface

Tatsuya Takimoto,* Hirohito Tsue, Rui Tamura, and Hideaki Sasaki

*Division of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586, Japan

Abstract

The solid-liquid adsorption behavior of p-tert-butylcalix[4]thiacrown-5 for heavy metal picrates has been studied. Of four heavy metal ions examined herein, mercury(II) ion was selectively adsorbed, and the saturated adsorption capacity reached to 7.3 ± 0.5 mg g–1.

Supporting Info. (59KB)PDF (217KB)

Published online: 1st October, 2014

Review | Special issue | Prepress
DOI: 10.3987/REV-14-SR(K)3
Terpenoids bearing the 7-Oxabicyclo[2.2.1]heptane (7-Oxanorbornane) Skeleton. Natural Sources, Biological Activities and Chemical Synthesis

Silvia Roscales and Joaquín Plumet*

*Química Orgánica, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid, Spain

Abstract

Compounds bearing the 7-oxabicyclo[2.2.1]heptane (7-oxanorbornane) subunits have been used extensively in the synthesis of a large array of complex organic structures. The ease of synthesis of compounds having this substructure in enantiomerically pure form, using Diels-Alder chemistry, is today an almost routinely experimental work. Moreover, the reactivity of these compounds, easily controllable and almost always associated to its ring-strain, makes them particularly valuable chiral building blocks. However, the presence of compounds showing this bicyclic skeleton in Nature has attracted less attention despite its relatively broad distribution. Many of these compounds have been shown to possess important biological activities presenting, in cases, unprecedented biogenetic origin. In addition, some of them have been considered as convenient synthetic targets enabling the development of new synthetic methodologies. In this article we have reviewed different families of terpenoids having in its structure this bicyclic subunit, paying particular attention to their natural sources, biosynthesis, biological activity and chemical synthesis.

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Published online: 30th September, 2014

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-14-13068
Isocoumarins from the Bark of Lindera Caudata

Yan-qing Ye, Cong-Fang Xia, Juan-Xia Yang, Yu-Chun Yang, Xue-Mei Gao, Gang Du, Hai-Ying Yang, Yin-Ke Li, and Qiu-Fen Hu*

*Key Laboratory of Ethnic Medicine Resource Chemistry, State Ethnic Affairs Commission & Ministry of Education, School of Chemistry and Biotechnology, Yunnan University of Nationalities, Kunming, Jingming South Road, Chenggong New District, Kunming, Yunnan 650500, China

Abstract

Three new isocoumarins, caudacoumarin A - C (1 - 3), together with two known isocoumarins (4 - 5) were isolated from the bark of Lindera caudata. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D- NMR techniques. The anti-tobacco mosaic virus (anti-TMV) activities of 1 - 5 were evaluated. The results revealed that compounds 1 - 5 showed modest anti-TMV activity with inhibition rate of 14.8 - 24.5%, respectively

Supporting Info. (151KB)PDF (166KB)

Published online: 29th September, 2014

Paper | Regular issue | Prepress
DOI: 10.3987/COM-14-13082
Syntheses of Acridines and Quinazoline-2,4(1H,3H)-dithiones by Rearrangements of N-Heterocyclic Carbenes of Indazole

Zong Guan, Mimoza Gjikaj, and Andreas Schmidt*

*Institute of Organic Chemistry, Clausthal University of Technology, Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany

Abstract

N-Heterocyclic carbenes of indazole which are arylated at N1 (1-aryl-indazol-3-ylidenes) have been generated by deprotonation of the corresponding indazolium salts. On deprotonation with potassium carbonate, potassium phosphate or tert.-butanolate in dioxane or toluene at reflux temperature, a rearrangement to acridines took place. Deprotonation with n-butyllithium in THF at room temperature in the presence of carbon disulfide gave quinazoline-2,4(1H,3H)-dithiones by a new rearrangement reaction.

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Published online: 26th September, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)87
Marine Natural Occurring 2,5-Diketopiperazines: Isolation, Synthesis and Optical Properties

Rémi Laville, Thanh Binh Nguyen, Céline Moriou, Sylvain Peteck, 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.

Supporting Info. (4.3MB)PDF (335KB)

Published online: 26th September, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)81
Synthesis of 1,2-Dialkynyldisilanes incorporated in 10-Membered-Ring System

Yoshiyuki Mizuhata, Yasunobu Egawa, Takahiro Sasamori, and Norihiro Tokitoh*

*Division of Synthetic Chemistry, Organoelement Chemistry, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan

Abstract

The reduction of a bis(dichloroethynylsilane) bridged by o-xylylene by lithium naphthalenide afforded trans- and cis-isomers of novel 10-membered-cyclic disilanes. Their structures were characterized by X-ray crystallographic analysis, showing the strain around the CC bonds and the close distances between two ethynylene moieties.

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Published online: 26th September, 2014

Paper | Regular issue | Prepress
DOI: 10.3987/COM-14-13075
Fluorinated β-Diketo Phosphorus Ylides: Their Cyclocondensation with Amidines Affording 4-Trifluoromethyl- and 4-Perfluoroalkyl-Substituted Pyrimidines

Ryosuke Saijo, Genki Watanabe, Ken-ichi Kurihara, and Masami Kawase*

*Faculty of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime 790-8578, Japan

Abstract

A study is presented for the syntheses of a series of 4-trifluoromethyl- and 4-perfluoroalkyl-substituted pyrimidines from the reaction of trifluoromethyl or perfluoroalkyl β-diketo phosphorus ylides (Ph3P=C(CORF)COR) with amidine hydrochloride.

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Published online: 26th September, 2014

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-14-13085
Synthesis of Novel β-Lactam Hybrids of Phenstatin and Other Substituted Aromatics as New Bioactives

David P. Brown,* Haoran Zhao, Julkernine M. Khondoker, Jatin R. Bhavsar, and Cecil C. Sigamoney

*Department of Chemistry, St. John's University, 8000 Utopia Parkway, Jamaica, New York 11439, U.S.A.

Abstract

Novel β-lactam hybrids have been synthesized as new chemical entities in the development of new antibiotic antineoplastic agents.

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Published online: 25th September, 2014

Review | Regular issue | Prepress
DOI: 10.3987/REV-14-805
Synthetic Approaches to Spiro-oxindoles and Iminoindolines Based on Formation of C2–C3 Bond

Chihiro Tsukano and Yoshiji Takemoto*

*Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-machi, Sakyo-ku, Kyoto 606-8501, Japan

Abstract

Spirooxindole and iminoindoline structures can be found in a wide range of complex natural products, and compounds containing these groups invariably display interesting biological activities. Considering their interesting biological properties and complex architecture, significant research efforts have been directed towards developing new synthetic methods for constructing these structures. This review summarizes our studies towards developing novel synthetic strategies capable of accessing these structures, as well as the applications of these methods to synthesizing natural products, including elacomine and dehaloperophoramidine.

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Published online: 22nd September, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)108
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*

*Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Teikyo University, 1091-1 Suarashi, Midori-ku, Sagamihara, 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).

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Published online: 22nd September, 2014

Paper | Regular issue | Prepress
DOI: 10.3987/COM-14-13072
Synthesis and Antimicrobial Evaluation of Some New Dihydropyridine, Pyrazole, Chromene, Pyrrole, Thiazole and Thiophene Derivatives

Ahmed A. Fadda,* Hala M. Refat, Khaled S. Mohamed, and Nada A. H. Mohamed

*Department of Chemistry, Faculty of Science, University of Mansoura, Mansoura 35516, Egypt

Abstract

Synthesis of 2-cyano-N-((2-methoxynaphthalen-1-yl) methylene)acetohydrazide (3) and used as key intermediate for the synthesis of some new heterocyclic compounds such as dihydropyridines (4, 6 and 8), pyrazoles (9 and 10), chromene (11), pyrroles (12 and 13), thiazoles (14 and 17) and thiophene (18-20) derivatives. The structures of newly synthesized compounds have been established on the basis of their IR, 1H-NMR, 13C-NMR and mass spectral data and have been screened for their antimicrobial activity

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Published online: 19th September, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)39
An Efficient Domino Sonogashira/Double Carbopalladation/C–H-Activation Reaction Leading to Fluorescent Polycyclic Aromatic Hydrocarbons

Lutz F. Tietze* and Christoph Eichhorst

*Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstr. 2, D-37077 Göttingen, Germany

Abstract

A facile synthesis of fluorescent polycyclic aromatic hydrocarbons through a highly productive palladium-catalyzed fourfold domino Sonogashira/double carbopalladation/C–H-activation process was developed.

Supporting Info. (1.4MB)PDF (376KB)

Published online: 19th September, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)109
Synthesis and Structural Analysis of Nine-Membered Enyne Nitrogen Heterocycles

Kazunobu Igawa, Takeshi Kawabata, Kazuhiro Uehara, and Katsuhiko Tomooka*

*Institute for Materials Chemistry and Engineering (IMCE), Kyushu University, 6-1, Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan

Abstract

An efficient approach to the nine-membered enyne nitrogen heterocycle 3 is presented. 1H NMR analysis reveals that both 3a (R = H, X = Ts) and 3b (R = Me, X = Ts) exhibit significant labile planar chirality in solution at ambient temperature. The X-ray analysis of 3b shows that the enantiotopic faces of the alkene are differentiated by the alkyne moiety in the solid state.

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Published online: 18th September, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)106
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).

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Published online: 16th September, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)97
Regioselective Introduction of Substituents to the meso-Position of Pyrromethenone Derivative – Application to the Synthesis of Sterically Fixed Phytochrome Chromophore Anchored to the C15 meso-Position

Yudai Tanaka, Ryoji Iwamoto, Ryo Sakata, Takahiro Soeta, Kohei Endo, Shuhei Fujinami, Katsuhiko Inomata, and Yutaka Ukaji*

*Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan

Abstract

Pyrromethenone derivatives corresponding to the CD-ring component of phycocyanobilin chromophore were regioselectively brominated with NBS at the meso-position retaining the stereochemistry of the olefinic carbon skeleton. Subsequent introduction of carbon-substituents to the brominated pyrromethenones was accomplished by treating with Grignard reagents to afford meso-alkylated (E)-isomers regardless of the stereochemistry of the starting brominated pyrromethenones. The resulting product was applied to the synthesis of a meso-anchored sterically fixed tetrapyrrole chromophore.

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Published online: 12th September, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)107
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.

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Published online: 11th September, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)83
Chiral Primary Amino Amide Alcohol Organocatalyst for the Asymmetric Michael Addition of 4-Hydroxycoumarin with α,β-Unsaturated Ketones

Jun Kumagai, Yoshihito Kohari, Chigusa Seki, Koji Uwai, Yuko Okuyama, Eunsang Kwon, and Hiroto Nakano*

*Department of Applied Chemistry, Graduate School of Engineering, Muroran Institute of Technology, 27-1 Mizumoto, Muroran, Hokkaido 050-8585, Japan

Abstract

Chiral primary amino amide organocatalysts were designed and synthesized as new organocatalysts for the enantioselective Michael addition of 4-hydroxycoumarin with α,β-unsaturated ketones to produce chiral warfarin (up to 56% ee with up to 92% yield).

PDF (602KB)

Published online: 11th September, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)99
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.

PDF (351KB)

Published online: 11th September, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)92
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.

Supporting Info. (494KB)PDF (751KB)

Published online: 10th September, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)96
Efficient Preparation of a Versatile Chiral Synthon for 1,2-Diamines via the Fe(III)-Catalyzed Diastereoselective Oxidation of 2-Imidazolone and Its Application

Hirofumi Matsunaga,* Iori Eshita, Shin Ando, and Tadao Ishizuka*

*Department of Pharmaceutical Sciences, Graduate School of Life Sciences, Kumamoto University, 5-1 Oe-hon-machi, Kumamoto 862-0973, Japan

Abstract

The efficient and predominant preparation of (4S,5S)-4,5-dimethoxy-2-imidazolidinone (DMIm) was established via the Fe(III)-catalyzed diastereoselective oxidation of 1-[(1S,2R)-2-exo-alkoxyapocamphanecarbonyl]-2-imidazolone with aqueous H2O2 up to 94% d.e., both of which were easily purified by column chromatography, followed by simple and convenient conversions. The obtained N-tosyl-(4S,5S)-DMIm proved to be a versatile chiral synthon for 1,2-diamines by the synthesis of (1S,2S)-1,2-diamino-1-(4-fluorophenyl)butane derivative, whose platinum complex showed potent antitumor activity.

PDF (670KB)

Published online: 8th September, 2014

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)98
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.

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Published online: 5th September, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)100
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.

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Published online: 3rd September, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)79
Simple, Selective, and Practical Synthesis of 2-Substituted 4(3H)-Quinazolinones by Yb(OTf)3-Catalyzed Condensation of 2-Aminobenzamide with Carboxamides

Tsutomu Yoshimura, Di Yuanjun, Yu Kimura, Hisatsugu Yamada, Akio Toshimitsu, and Teruyuki Kondo*

*Advanced Biomedical Engineering Research Unit, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan

Abstract

A simple, selective, and practical synthetic method of 4(3H)-quinazolinones is realized by Yb(OTf)3-catalyzed condensation of 2-aminobenzamide with carboxamides. As the reaction proceeds, NH3 and H2O were formed as byproducts; however, Yb(OTf)3 can operate as an efficient Lewis acid catalyst without deactivation.

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Published online: 3rd September, 2014

Paper | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)74
Simple Synthetic Method for 1-Hydroxyindole and Its Application to 1-Hydroxytryptophan Derivatives

Toshiya Kawasaki, Mutsuko Tabata, Kyoko Nakagawa, Kensuke Kobayashi, Atsushi Kodama, Tetsuya Kobayashi, Masakazu Hasegawa, Keiko Tanii, and Masanori Somei*

*Noto Marine Laboratory, Institute of Nature and Environmental Technology, Faculty of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University, 56-7 Matsuhidai, Matsudo-shi, Chiba 270-2214, Japan

Abstract

Simple and general synthetic method for 1-hydroxy- and 1-methoxyindole is reported. Its application to the synthesis of various types of 1-hydroxy- and 1-methoxyindole derivatives is successful, especially for the synthesis of 1-hydroxytryptophan derivatives.

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Published online: 2nd September, 2014

Communication | Special issue | Prepress
DOI: 10.3987/COM-14-S(K)65
Three-Component Coupling Reaction of Enynes, Carbonyls, and Organozinc Reagents

Yuki Ohira, Takamichi Mori, Maya Hayashi, Gen Onodera, and Masanari Kimura*

*Division of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

A mixture of t-butylzinc halide and an aldehyde reacts with enyne to provide homopropargyl alcohol in a 1,2-addition manner. Under carbon dioxide at atmospheric pressure, three components (t-butylzinc halide, enyne, and carbon dioxide) combine in a 1:1:1 ratio to give allenyl carboxylic acids in a 1,4-addition manner. These products are useful for the synthesis of heterocyclic compounds such as α,β-unsaturated γ-butyrolactones.

PDF (386KB)

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.

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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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