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Regular & Special Issues

39 data found. 1 - 30 listed Next Last

Published online: 21st August, 2019

Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14096
Synthesis of 4-Aroyl-5-Arylpyrazoles and 4-Aroyl-3-Arylpyrazoles Via The Reaction of Enaminodiketones with Substituted Hydrazines

Rika Kotouge, Takashi Nishiyama, Akira Yamauchi, Kanako Ono, Noriyuki Hatae, Tsutomu Oikawa, Satoshi Hibino, and Tominari Choshi*

*Graduate School of Pharmacy & Pharmaceutical Sciences, Fukuyama University, Fukuyama, Hiroshima 729-0292, Japan

Abstract

Pyrazole is a five-membered heterocyclic compound and is one of the important heterocycles in the fields of medicine and pharmacology. Here, we demonstrate the reactivity of symmetrical enaminodiketones 814 with substituted hydrazines. When using alkylhydrazines, if the substituent size of the alkyl group is small, it is possible to selectively synthesize 1-substituted 4-aroyl-5-arylpyrazoles and their regioisomers, 1-substituted 4-aroyl-3-arylpyrazoles, by choosing the solvent (EtOH or toluene). When they react with bulky substituted hydrazines (e.g., cyclohexyl, phenyl, or pyridyl), only 1-substituted 4-aroyl-5-arylpyrazoles are selectively obtained.

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Published online: 20th August, 2019

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14122
Platinum on Carbon–Catalyzed and Chemoselective Aqueous Oxygen Oxidation of Aromatic Acetals to Benzoic Acids

Naoki Yasukawa, Takumi Matsuda, Eisho Shimizu, Hironao Sajiki,* and Yoshinari Sawama*

*Laboratory of Organic Chemistry, Department of Pharmaceutical Sciences, Gifu Pharmaceutical University, 1-25-4 Daigakunishi, Gifu 501-1196, Japan

Abstract

Novel chemoselective transformations can diversify the synthetic pathways of the target molecules. The chemoselective oxidation of aromatic acetals to benzoic acid derivatives under platinum on carbon (Pt/C)–catalyzed oxygen oxidation conditions has been newly developed with a tolerance of aliphatic acetals and ketals. The present oxidation was clean and useful from the viewpoint of the easy removal of Pt/C and the use of molecular oxygen as a green oxidant in water as an abundant, non-toxic and environmentally friendly solvent.

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Published online: 19th August, 2019

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14104
Synthesis of N-Substituted Pyrrole Derivatives via Indium-Assisted One-Pot Reduction/N-Annulation Sequence Reaction

Eungyung Kim, Mingyeong Jeong, Hyejeong Lee,* and Byeong Hyo Kim*

*Department of Chemistry, Kwangwoon University, Seoul 01897, Korea

Abstract

A synthesis strategy toward diverse pyrrole derivatives via an indium-mediated one-pot reductive N-annulation reaction has been developed. This protocol provides easy access to versatile N-substituted pyrroles in the presence of an indium/AcOH co-activation promotor, with excellent yields.

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Published online: 19th August, 2019

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14137
An Ionic Liquid-Based Green Synthesis Strategy: Synthesis of Dihydropyrimidinones by Three-Component Biginelli-Type Reaction of Aliphatic Aldehydes, Aromatic Aldehydes and Urea

Lei-Han Fu, Zong-Bo Xie,* Guo-Qing Chen, Jin Lan, Zhi-Yu Hu, and Zhang-Gao Le*

*Department of Applied Chemistry, East China University of Technology, Guanglan Road 330013, China

Abstract

A Biginelli-type reaction involving aliphatic aldehydes, aromatic aldehydes, and urea was performed at high concentration with high regioselectivity to give a range of highly diverse 3,4-dihydropyrimidin-2-(1H)-one products in 58-88% yields, where a 30% aqueous solution of ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate) was employed as a green reaction medium. The catalyst can be easily recycled and reused with similar efficacy for at least four cycles.

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Published online: 16th August, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)21
Synthesis of Oxygen-Heterocycles Having Linker Components for Trapping Cysteine Derivatives

Eito Yoshioka, Ikko Minato, Hideki Takashima, and Hideto Miyabe*

*Laboratory for Medicinal Chemistry, School of Pharmacy, Hyogo University of Health Sciences, 1-3-6 Minatojima, Chuo-ku, Kobe City, 650-8530, Japan

Abstract

Tricyclic oxygen-heterocycles 10, 13a, 13b and 18 having a linker component were synthesized for the site-specific modification of proteins and peptides. The linker components were initially introduced by Sonogashira-Hagihara cross coupling of 5-bromo-2-hydroxybenzaldehyde 5 and a variety of alkynes. Next, the desired oxygen-heterocycles 10, 13a, 13b and 18 were synthesized by the condensation reaction of coupling products with cyclohexane-1,3-dione in the presence of N,N-diisopropylethylamine. Finally, the trapping ability of these oxygen-heterocycles was demonstrated by the representative reaction of oxygen-heterocycle 10 with glutathione 19 as a nucleophile having a thiol group.

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Published online: 16th August, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)29
Formation of Seven-membered-ring Fused Bithiophene Derivatives by Nosyl Annulation

Atsunori Mori,* Masayasu Hayashi, Mitsuru Matsuoka, Shiomi Ashida, Yukiko Ito, Kohei Hosokawa, Toyoko Suzuki, Kentaro Okano, Chi-Hsien Wang, and Masaki Horie

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

Abstract

Nosyl annulation of a bithiophene derivative with nosylamide (NsNH2) gives a 5-7-5 fused N, S-heterocyclic compound. The detailed molecular structure of the obtained nosylamide was analyzed by single-crystal X-ray crystallography. The obtained product was transformed into several amines and amides. The CBr bond at the fused heterocycle was also subjected to cross-coupling reactions, where the nosyl group was found to be tolerant.

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Published online: 16th August, 2019

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)43
Concise Synthesis of Tpca-1 and Related Thiophene-Carboxamides by Cross Coupling

Norihiko Kawasaki, Hayato Fukuda, and Jun Ishihara*

*Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

A synthesis of 5-substituted 2-[(aminocarbonyl)amino]-3-thiophene- carboxamides is described. The coupling reaction of 2-ureidothiophene- 3-carboxamide and various aryl compounds allows the concise approach of promising candidates for IKK-2 inhibitor, such as TPCA-1

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Published online: 15th August, 2019

Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14134
Synthesis and Antioxidant Activities of Some Novel Indane-Amide Substituted Pyrazole, Pyrimidine, Pyridine and 2-Pyrone Derivatives

Khaled S. Mohamed* and Elsherbiny H. El-Sayed

*Engineering Chemistry Department, Higher Institute for Engineering and Technology, New Damietta, New Damietta 34518, Egypt

Abstract

2-Cyano-N-(2,3-dihydro-1H-5-indenyl)-3-(dimethylamino)acrylamide (3) was used in synthetic paths to some novel indane-amide containing pyrazole, pyrimidine, fused pyrimidines, fused pyridines and 2-pyrone derivatives by reaction of 3 with various reagents. The newly synthesized compounds were investigated for their antioxidant activity. Some of the tested compounds exposed auspicious activities.

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Published online: 14th August, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)25
Photo-irradiation-promoted Aminoetherification of Glycals with N-Acyliminoiodinane and Alcohols

Sota Masakado, Yusuke Kobayashi, and Yoshiji Takemoto*

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

Abstract

An efficient trifluoroacetamido-etherification of glycals was achieved using N-acyliminoiodinane and various alcohols under photo-irradiation. This reaction was successfully applied to the efficient synthesis of biologically active compounds.

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Published online: 13th August, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)31
Oxidative C-C Bond Cleavage of N-Protected Cyclic Amines by HNO3-TFA System

Kosuke Yamamoto, Hiroyuki Toguchi, Toshihiro Harada, Masami Kuriyama, and Osamu Onomura*

*Graduate School of Biomedical Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

Oxidative C-C bond cleavage of N-protected cyclic amines was achieved by using 70% HNO3 in trifluoroacetic acid (TFA) to afford ω-amino acid derivatives in high yields. The C-C bond cleavage reaction smoothly proceeded under aerobic condition with a simple procedure. The use of 70% HNO3 as an oxidant source enabled to conduct the reaction at a higher substrate concentration than that of the previous condition using NaNO2 in TFA. In addition, some ω-amino acids were obtained with improved reaction efficiency under the present reaction conditions.

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Published online: 13th August, 2019

Communication | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)39
Synthesis of Dibenzoxazonines by Domino (2+2) Cycloaddition—4π Electrocyclic Ring Opening Reaction of Cyclic Imines with Ynamides

Kiyosei Takasu,* Masaki Tsutsumi, Tomohiro Ito, Hiroshi Takikawa, and Yousuke Yamaoka

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

Abstract

Dibenzo[b,h][1,4]oxazonines and the thiazonine congener were synthesized from cyclic imines with ynamides by acid-mediated domino (2+2) cycloaddition—4π electrocyclic ring opening reaction. The reaction enables two carbon-enlargement of the cyclic imine substrates. The X-Ray crystallography made clear that the oxazonine skeleton has a unique bent-conformation.

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Published online: 13th August, 2019

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14128
Synthesis and the First Structure–Activity Relationship Study of Imidazole Alkaloid from Red Ascidian as Aldose Reductase Inhibitors

Kenta Morikawa, Sota Uno, Shoko Higashi, Masaru Goto, and Ryota Saito*

*Department of Chemistry, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan

Abstract

We synthesized a series of 2-aroyl-4-aryl-1H-imidazoles (2 and 3) and evaluated their in vitro AR inhibitory activity for the first time. We observed improved activities with derivatives having multiple catechol moieties.

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Published online: 13th August, 2019

Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14129
Ruthenium-Catalyzed Hydroxyethylation of Cyclic Amines with Ethylene Glycol

Yushi Nakamura, Shuhei Tomioka, Yohei Oe,* and Tetsuo Ohta

*Department of Biomedical Information, Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara-miyakodani, Kyotanabe, Kyoto 610-0394, Japan

Abstract

It was found that a catalyst system RuCl2(PPh3)3/Xantphos is effective to install hydroxyethyl groups to the nitrogen atom of cyclic amines. Thus, the reactions of cyclic amines with ethylene glycol were performed in the presence of the RuCl2(PPh3)3/Xantphos catalyst in toluene at 120 °C for 22 h to provide the corresponding β-amino alcohols in up to 92% yield.

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Published online: 8th August, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)24
Synthesis and Hybridizing Property of Oligonucleotides Including 2′-C,4′-C-ethyleneoxy-bridged 2′-Deoxyadenosine with an Exocyclic Methylene Unit

Takashi Osawa, Yoshinori Onishi, Sawako Wakita, Yuta Ito, and Yoshiyuki Hari*

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

Abstract

2,4-Bridged nucleic acids (2,4-BNAs) are of interest because oligonucleotides that include them have excellent duplex-forming capability and high nuclease resistance compared to natural oligonucleotides. We have recently developed 2′-C,4′-C-ethyleneoxy-bridged thymidine with an exocyclic methylene unit (methylene-EoDNA-T) as a novel 2,4-BNA analog. Oligonucleotides that include methylene-EoDNA-T have marked hybridizing capability, nuclease resistance, and in vitro gene-silencing potency. In the present study, we designed and synthesized a 2-deoxyadenosine analog of methylene-EoDNA (methylene-EoDNA-A), and incorporated it into oligonucleotides. The results of melting temperature (Tm) analysis of duplexes formed from methylene-EoDNA-A-modified oligonucleotides indicated that the hybridizing capability with regard to complementary DNA was almost the same or slightly higher than that of natural DNA. Moreover, methylene-EoDNA-A:methylene-EoDNA-T base pairs increased the thermal stability of DNA duplexes compared to that of DNA duplexes containing methylene-EoDNA-A- or methylene-EoDNA-T-modification in one strand.

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Published online: 7th August, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)19
A Mild Bischler–Napieralski-Type Cyclization of Trichloromethyl Carbamates for the Synthesis of β-Carbolinones

Seiya Hirao, Mayumi Kitamori, Tomoki Itoh, Yuusuke Chiba, and Takumi Abe*

*Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan

Abstract

A straightforward synthesis of β-carbolinones by the Bischler–Napieralski-type cyclization of the corresponding trichloromethyl carbamates, which does not require acids, bases, oxidants, or transition-metals to promote the cyclization, has been achieved.

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Published online: 7th August, 2019

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)26
Intramolecular Oxa-Michael Reactions of Aldols Generated from Enones and Isatins to Afford Spirooxindole Tetrahydropyrans

Maira Pasha, Muhammad Sohail, and Fujie Tanaka*

*Chemistry and Chemical Bioengineering Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Okinawa 904-0495, Japan

Abstract

Spirooxindole derivatives are found in bioactive natural products and are used in drug discovery and related research. Here, acid-catalyzed diastereoselective intramolecular oxa-Michael cyclization reactions of β-hydroxyenones generated from enones and isatin derivatives that afford spirooxindole tetrahydropyrans are reported. The major diastereomers of the products of these reactions were previously difficult to access by the amine-catalyzed hetero-Diels-Alder reactions of enones with isatins. With the use of enantiomerically enriched forms of the starting materials in the reactions, enantiomerically enriched spirooxindole tetrahydropyrans that retained the enantiopurities of the starting materials were obtained.

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Published online: 7th August, 2019

Review | Special issue | Prepress
DOI: 10.3987/REV-19-SR(F)2
Mini-Review: The Chemistry of Vorapaxar – Is There Any Room for Improvement Left?

Piotr P. Graczyk* and Sven Nerdinger

*Selvita Services Sp. z o. o., Bobrzynskiego 14, 30-348 Krakow, Poland

Abstract

Based on the case of Vorapaxar, this review describes the key role of an early chemistry effort to enable rapid discovery of an optimal synthetic route to a commercially important product. The intramolecular Diels-Alder (IMDA) reaction developed by scientists from Schering to make natural product Himbacine in mid-‘90s allowed formation of the Vorapaxar’s backbone almost 10 years later. Since then this strategy has been followed by all companies. Additional improvements by Schering to the synthesis of Vorapaxar greatly limited the opportunities for generic manufacturers to secure new intellectual property. Most of the chemistry presented in this review comes from the patent applications and as such has not been subjected to rigorous peer review, but in our opinion this paper may serve as helpful information for readers in the area of drug discovery.

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Published online: 7th August, 2019

Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14110
Synthesis and Biological Evaluation of 3-((1-Methyl-1H-pyrrol-2-yl)methylene)indolin-2-one Derivatives as Potent Anticancer Active Agents

Jie Chen, Wei-nan Hu, Yang Xu, Wen Li, Ya-yun Qi, Yi-hong Fu, Jia-min Liu, Zhen-chao Wang,* and Gui-ping Ouyang*

*College of Pharmacy, Guizhou University, Huaxi St., Guiyang 550025, China

Abstract

A series of 3-((1-methyl-1H-pyrrol-2-yl)methylene)indolin-2-one derivatives were designed, synthesized, and evaluated for their inhibition activities against four tumor cells in vitro. These compounds were fully characterized by 1H NMR, 13C NMR, and HRMS. Antitumor experiments indicated that some compounds exhibited significant inhibition activities against SMMC-7721. Especially, the IC50 values of 7k and 7l (IC50 = 8.08 ± 0.95 µM, IC50 = 3.01 ± 0.61 µM) demonstrated the best antitumor activities against SMMC-7721 (human hepatoma cell lines) than the positive agents Sunitinib (IC50 = 8.27 ± 0.40 µM). Likewise, their structure activity relationship (SAR) was studied.

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Published online: 7th August, 2019

Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14127
Synthesis of 8-Oxa-2-azabicyclo[3.2.1]octane Using a 1,3-Dipolar Cycloaddition Reaction

Kazuhiro Higuchi,* Yoshiki Matsubayashi, Takuma Sakurai, Motoki Ito, and Shigeo Sugiyama

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

Abstract

Herein, we report the application of 1,3-dipolar cycloaddition reaction toward the synthesis of a variety of 8-oxa-2-azabicyclo[3.2.1]octane compounds, the core structure of atkamine. The target compounds were obtained using a combination of a vinyl ether and carbonylylide, which was generated from a diazo compound and rhodium catalyst, in the presence of a Lewis acid.

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Published online: 6th August, 2019

Review | Special issue | Prepress
DOI: 10.3987/REV-19-SR(F)1
Recent Advances in the Chemistry of Azaazulenes and Related Compounds

Noritaka Abe*

*Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan

Abstract

In this review, the synthetic methods and about the biological and physical properties of mono- and poly-azaazulenes including some of their dihydro-, tetrahydro-, oxo-derivatives and aromatics- and heterocycles-fused derivatives and related compounds, such as pyrrolobenzazepines, azepinoindole derivatives, and so on, published from end of 2017 to April 2019, are surveyed.

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Published online: 5th August, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)16
Pyridine-directed Rh-catalyzed C6-selective C–H Acetoxylation of 2-Pyridones

Sunit Hazra, Koji Hirano,* and Masahiro Miura*

*Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan

Abstract

A Rh(III)-catalyzed C-H acetoxylation of 2-pyridones with phenyliodine(III) diacetate (PIDA) in a DCE/AcOH mixed solvent system has been developed using N-2-pyridyl function as directing group. The reaction occurs under mild conditions, typically in air at 40 oC, to selectively produce the corresponding C6-acetoxylated 2-pyridones in moderate to good yields.

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Published online: 1st August, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)23
Conformational Properties and M1 Antimuscarinic Activity of 4-Substituted Pirenzepine/Telenzepine Analogues

Yuki Kanase, Kosho Makino, Takashi Yoshinaga, Hidetsugu Tabata, Tetsuta Oshitari, Hideaki Natsugari, and Hideyo Takahashi*

*Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan

Abstract

The atropisomeric and conformational properties of the 4-Cl/Me-substituted pirenzepine/telenzepine analogues were examined. Although the 4-substitution is not effective in reducing the rotational barrier of the N5–(C1'=O) bond, the butterfly motion of the tricyclic ring system was frozen. The atropisomers showed little racemization after heating at 80 °C for 5 days. While these analogues showed less affinity to the M1 receptor compared with pirenzepine, a ca. 4.4-fold difference in potency between the atropisomers was observed for 1b.

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Published online: 31st July, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)13
Gold(I)-Catalyzed 10-endo-dig-Selective Cycloisomerization of N-(2-Anilinobenzyl)propargylamines

Mamoru Ito,* Daisuke Inoue, Asahi Takaki, Kyalo Stephen Kanyiva, 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

The cationic gold(I)-catalyzed 10-endo-dig-selective cycloisomerization of N-(2-anilinobenzyl)propargylamine derivatives was developed. The reaction proceeded smoothly under mild conditions to give dibenzodiazecines. The catalytic construction of an entropically and enthalpically disfavored ten-membered ring was achieved by using a highly nucleophilic 3,5-dimethoxyanilino group as a reaction site.

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Published online: 30th July, 2019

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)15
Synthesis of Axially Chiral Binaphthothiophene δ-Amino Acid Derivatives Bearing Chalcogen Bonds

Shohei Hamada, Shuo Wang, Takuya Murai, Yongning Xing, Takumi Inoue, Yoshihiro Ueda, Takahiro Sasamori, Takeo Kawabata, and Takumi Furuta*

*Department of Pharmaceutical Chemistry, Kyoto Pharmaceutical University, 1 Misasagi-Shichonocho, Yamashina, Kyoto 607-8412, Japan

Abstract

Axially chiral binaphthothiophene amino acid was synthesized as a stable artificial δ-amino acid. N- and C-protected derivatives of this unnatural amino acid were also prepared and applied for derivatization to the dipeptide. The crystal structure of the dipeptide revealed that the carbonyl groups of both the amide and the ester moieties were fixed with naphthothiophene rings in coplanar geometry via intramolecular chalcogen bonds.

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Published online: 30th July, 2019

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-19-14114
Environmentally Friendly Synthesis of N-Methylated Nitrogen Heterocycles from an Aqueous Solution of Methylamine and Diols

Akane Enomoto, Takuya Shimbayashi, and Ken-ichi Fujita*

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

Abstract

N-Methylated nitrogen heterocycles are important compounds which are very common in organic, pharmaceutical, and material chemistry. Development of new environmentally friendly catalytic methods for the synthesis of N-methylated heterocycles using cost-effective and readily-available starting materials is strongly demanded. Herein, we report the efficient synthesis of N-methylated heterocycles using readily-available aqueous solution of methylamine and various diols catalyzed by iridium complexes. This catalytic system is attractive because of its high atom economy exhausting water as a sole by-product.

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Published online: 26th July, 2019

Communication | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)17
Synthesis of Novel Fluorous Imidazolium Ionic Liquids

Mitsunori Honda,* Ryu Nakajima, Ko-Ki Kunimoto, and Masahito Segi*

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

Abstract

The synthesis of a novel class of fluorous ionic liquids was investigated. The 1,3- and 1,2-diperfluoroalkylated imidazolium salts 1 and 2 were successfully prepared. Unfortunately, most of them were solids and had low fluorophilicity. On the other hand, most imidazolium salts 3-8 possessing one or two tris(perfluoroalkyl)silyl groups in cation moiety were liquids at room temperature and had high fluorophilicity independent of the kind of anion moiety. Additionally, dicationic bisimidazolium ionic liquids 10 having two tris(tridecafluorooctyl)silylpropyl groups were also prepared and showed good fluorophilicity.

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Published online: 24th July, 2019

Communication | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)22
One-Pot Synthesis of 9-Spirofluorenes via Tandem Copper-catalyzed Arylative Cyclization and Spirocyclization of Biaryl-substituted Alkynyl Alcohols

Noriko Okamoto, Takuya Sueda, and Reiko Yanada*

*Faculty of Pharmaceutical Sciences, Hiroshima International University, 5-1-1, Hirokoshingai, Kure, Hiroshima, 737-0112, Japan

Abstract

A tandem copper-catalyzed arylative cyclization and spirocyclization strategy to access spiro cyclic compounds is described. This method enables the one-pot construction of 9-spirofluorenes from readily available alkynyl alcohols with biaryl-substituents via the copper-catalyzed arylative ring-closing reaction and the Friedel–Crafts reaction.

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Published online: 24th July, 2019

Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)10
Iridoid Glucosides from Linociera sangda

Yukiko Takenaka, Naoaki Okazaki, Toyoyuki Nishi, Naotaka Nagakura, and Takao Tanahashi*

*Kobe Pharmaceutical University, 4-19-1 Motoyamakita-machi, Higashinada-ku, Kobe 658-8558, Japan

Abstract

A phytochemical investigation of the aerial parts of Linociera sangda led to the isolation of three new iridoid glucosides (13), together with nine known iridoid glucosides and a flavonoid glycoside, nicotiflorin. The structures of the new compounds were elucidated spectroscopically. Compounds 13 are members of a rare group of iridoids with a spirolactone ring, and compound 3 is the first instance of an adduct of iridoid glucoside and flavonoid glycoside.

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Published online: 22nd July, 2019

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)12
Synthesis and Physical Properties of π-Extended Molecules Having p-Methylenequinone Unit

Rui Umeda,* Masamichi Nakatsukasa, and Yutaka Nishiyama*

*Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680, Japan

Abstract

In this paper, we reported the facile synthesis of the π-extended molecules having p-methylenequinone unit from the aromatic ketones, such as fluorenone, xanthone, thioxanthone, dibenzosuberenone, and acridone, in few steps and the results of their physical properties.

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Published online: 19th July, 2019

Communication | Special issue | Prepress
DOI: 10.3987/COM-19-S(F)18
Rapid Exploration of Novel Anthelmintic Agent from Alkyne-Bearing Avermectin Derivative via Click Chemistry

Tomoyasu Hirose, Akari Ikeda, Ayumi Tsutsui, Satoshi Ōmura, and Toshiaki Sunazuka*

*The Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641

Abstract

We applied copper-catalyzed 1,4-disubstituted-1,2,3-triazole formation, a major connective reaction in “Click Chemistry”, to synthesize novel avermectin derivatives. Among the synthetic triazole-containing avermectins, the 4-hydroxybutyltriazole derivative (3a) was found to demonstrate notable antinematodal activity against ivermectin-resistant Trichinella spiralis in vitro. Furthermore, a new compound (3a) also exhibited strong antinematode properties against ivermectin-resistant Haemonchus contortus in sheep following oral administration.

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39 data found. 1 - 30 listed Next Last