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Published online: 12th August, 2020

Paper | Regular issue | Prepress
DOI: 10.3987/COM-20-14314
A One-Pot Four-Component Procedure for the Synthesis of Dispiro[tetrahydroquinoline-bis(2,2-dimethyl-1,3-dioxane-4,6-dione)] Derivatives

Zhaohui Xu,* Yexuan Tang, Qiang Xiao, and Chuanwen Liao*

*Department of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P.R. China.

Abstract

A simple and efficient procedure for the diastereoselective synthesis of dispiro[tetrahydroquinoline-bis(2,2-dimethyl-1,3-dioxane-4,6-dione)] derivatives through one-pot four-component reaction of aromatic aldehydes, 2,2-dimethyl-1,3-dioxane-4,6-dione, arylamines and acetone in the presence of potassium dihydrogen phosphate (KDP) is described. The procedure involves initial Knoevenagel reaction, followed by Diels-Alder, Michael additon and intramolecular reactions. The main advantages of the protocol are the high isolated yields, broad substrate scope, mild conditions, and easy operation.

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Published online: 7th August, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)18
Copper-Mediated Trifluoromethylation of Borylporphyrins Using An in Situ-Generated CF3 Radical from NaSO2CF3 and tert-Butyl Hydroperoxide

Satoshi Hayashi,* Daisuke Yamazaki, and Toshikatsu Takanami*

*Department of Life and Pharmaceutical Sciences, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan

Abstract

We developed a method for the copper-mediated reaction of borylated Ni(II) porphyrins using NaSO2CF3 (Langlois’ reagent) and tert-butyl hydroperoxide (TBHP) to prepare trifluoromethylated Ni(II) porphyrins.Porphyrin trifluoromethylation can be carried out under mild conditions and exhibits both excellent substrate generality and functional group compatibility.

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Published online: 7th August, 2020

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-20-14320
Ukixanthomycin A: a Hexacyclic Xanthone from the Mudflat-Derived Actinomycete Streptomyces sp.

Yuhei Koyanagi, Teppei Kawahara, Yuki Hitora, and Sachiko Tsukamoto*

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

Abstract

A new hexacyclic xanthone, ukixanthomycin A (1), was isolated from the mudflat-derived Streptomyces sp. HGMA004 by screening based on chemical analysis by UPLC-HRMS with our in-house actinomycete extract library. The structure of 1 was elucidated by spectral analyses and quantum chemical calculations. Compound 1 showed weak antifungal activity against Candida albicans.

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Published online: 4th August, 2020

Paper | Regular issue | Prepress
DOI: 10.3987/COM-20-14312
Design and Synthesis of 4'-Cyano Dideoxy Isonucleosides and Their Activity against HIV-1 and HBV

Kengo Onitsuka, Kakeru Yamaguchi, Ryoh Tokuda, Nobuyo Higashi-Kuwata, Shunsuke Kuwahara, Hiroki Kumamoto, Kenji Maeda, Kazuhiro Haraguchi, Hiroaki Mitsuya, and Shuhei Imoto*

*Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1, Ikeda, Kumamoto-shi, 860-0082, Japan

Abstract

Nucleoside reverse-transcriptase inhibitors are major antiviral agents against HIV-1 and HBV. Here, we describe the synthesis of a novel 4'-cyano dideoxy isonucleoside 6 and its phosphoramidate prodrug 7. Intermediate 16 is a promising precursor for the preparation of isonucleosides bearing substituents at the 4' position with various nucleobases. In addition, 6 and 7 were evaluated for their antiviral properties against HIV-1 and HBV. Compound 7 displayed weak anti-HIV activity (EC50 = 61.4 μM) and had no observed cytotoxicity in two different cell systems.

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Published online: 3rd August, 2020

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-20-14309
Change in the Fluorescence of 1,1′-Diaryl-2,2′-biimidazoles upon the Addition of Acid

Shoji Matsumoto,* Seigi Tachibana, and Motohiro Akazome

*Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

Abstract

The optical properties of a series of 1,1′-diaryl-2,2′-biimidazoles were examined. Different transitions were observed in their fluorescence spectra upon changing the electronic properties of the phenyl ring at the C1 and C1′ positions. The presence of a formyl group on the phenyl ring results in fluorescence via a CT transition with a solvent effect. A bathochromic change was observed when HCl was added to a solution of compound bearing a methoxy group in CH2Cl2, whereas a hypsochromic change was observed in compound bearing a formyl group. These observations were attributed to the protonation, which causes a characteristic change in their biimidazole moieties.

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Published online: 30th July, 2020

Communication | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)22
Catalytic Enantioselective Oxa-Hetero-Diels-Alder Reactions of Enones with Aryl Trifluoromethyl Ketones: Synthesis of Tetrahydropyranones

Maira Pasha 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

Diastereo- and enantioselective oxa-hetero-Diels-Alder reactions of enones with aryl trifluoromethyl ketones that afford tetrahydropyranone derivatives catalyzed by an amine-based catalyst system are reported. The major diastereomers of the tetrahydropyranone products obtained in these reactions had the relative stereochemistry different from that of the previously synthesized tetrahydropyranone derivatives.

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Published online: 29th July, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)17
Identification of a Novel Indoleamine 2,3-Dioxygenase Inhibitor Bearing an Eight-Membered Ring Fused Indole Scaffold and Its Structure-Activity Relationship

Ayuta Yamaguchi, Shinsuke Inuki,* Katsumi Ohta, Shinya Oishi, Akira Asai, and Hiroaki Ohno*

*Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan

Abstract

Indoleamine 2,3-dioxygenase 1 (IDO1) is a promising target for cancer immunotherapy because it is overexpressed in a variety of tumor cells. IDO1 also plays an important role in the process of immune escape by tumors. In this study, we identified a novel IDO1 inhibitor KPYC12532 (5a) bearing an eight-membered ring-fused indole scaffold by screening our compound library. To develop novel IDO1 inhibitors, we conducted a structure-activity relationship study of 5a and found some compounds displaying comparable activity. These results provide useful insight for the design of novel IDO1 inhibitors.

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Published online: 17th July, 2020

Review | Special issue | Prepress
DOI: 10.3987/REV-20-SR(K)2
Environmentally Benign Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide using Binary and Bifunctional Catalysts

Ken Okuno, Ryuichi Nishiyori, Mana Hiraki, and Seiji Shirakawa*

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

Abstract

The extensive utility of five-membered cyclic carbonates has been well established in the chemical industry. Among the various methods available for the synthesis of five-membered cyclic carbonates, coupling reactions that involve epoxides and carbon dioxide are ideal. This review introduces environmentally benign catalytic systems for the synthesis of cyclic carbonates under mild reaction conditions. Application of chiral catalysts to the asymmetric synthesis of optically active cyclic carbonates is also discussed.

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Published online: 17th July, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)15
Selective Reduction and Dihydroxylation of α,β-Unsaturated Esters in The Presence of Enals: One-Pot Synthesis of A 2,5-Disbstituted Tetrahydrofuran

Kenta Morita, Kenichi Murai, Mitsuhiro Arisawa, and Hiromichi Fujioka*

*Graduate School of Pharmaceutical Science, Osaka University, 1-6 Yamadaoka, Suita, Osaka 560-0871, Japan

Abstract

Two-way discriminative conversion, reduction and dihydroxylation of α,β-unsaturated esters were achieved in the presence of enals using two phosphonium salts as in situ protecting groups. Furthermore, a pot-economical one-pot synthesis of a tetrahydrofuran derivative was achieved.

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Published online: 9th July, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)21
Regiodivergent Ring Opening Reactions of 2-Arylated 3-Nitrocyclopropane-1,1-Dicarboxylates Leading to Polyfunctionalized Dipoles

Haruyasu Asahara,* Rikiya Kamidate, and Nagatoshi Nishiwaki*

*Pharmaceutical Science, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0821, Japan

Abstract

Two kinds of Lewis acid induced ring-opening reactions of 2-aryl-3-nitrocyclopropane-1,1-dicarboxylates proceeded to afford 5-aryl-2-isoxazolines and γ-keto acid derivatives, respectively. Different ring-opening modes could be controlled by choosing the ligand or solvent.

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Published online: 3rd July, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-934
Aryne-Mediated Synthesis of Oxygen Heterocycles and Application to Cysteine-Selective Trapping

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

The use of arynes as the highly reactive intermediates in organic synthesis has attracted substantial attention. Particularly, the introduction of ortho-(trimethylsilyl)aryl triflates as easily activatable aryne precursors led to growing activity in this field. Most reactions using these aryne precursors proceed through the addition of nucleophiles to arynes and the subsequent trapping with electrophiles to give the multisubstituted arenes with structural diversity and complexity. Based on our studies, this review highlights the insertion of arynes, generated from ortho-(trimethylsilyl)aryl triflates, into C=O π-bond of formamides. Initially, the representative examples for formal [2+2] cycloaddition of arynes with the carbon–heteroatom double bond or the heteroatom–heteroatom double bond are shown. Next, the studies on the insertion of arynes into the N−C and C=O bonds of amide group including our three-component coupling reaction leading to oxygen heterocycles are summarized. The SN2’ reaction of tricyclic oxygen heterocycles, obtained by three-component coupling reaction, was studied by using carbon and sulfur nucleophiles. The SN2’ reaction was expanded to four-component coupling reaction. Finally, the application of tricyclic oxygen heterocycles to cysteine-selective trapping is described.

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Published online: 23rd June, 2020

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)12
Bifunctional-Benzothiadiazine-Catalyzed Regio- and Stereoselective Aldol Reactions using A 1,3-Acetonedicarboxylic Acid Monoester

Yusuke Tokuhiro, Noboru Hayama, Yusuke Kobayashi, and Yoshiji Takemoto*

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

Abstract

Regio- and stereoselective decarboxylative aldol reactions of a 1,3-acetonedicarboxylic acid monoester were achieved using an aminobenzothiadiazine organocatalyst. The products were obtained with perfect regioselectivity and moderate to good enantioselectivity using various aromatic aldehydes. Subsequently, the thus obtained adducts were efficiently converted into various chiral building blocks.

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Published online: 23rd June, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)14
Synthesis of Pyrrolo[2,3-C]Quinoline Alkaloid Marinoquinolines

Takashi Nishiyama, Mari Murakami, Kimiko Taninaka, Erina Hamada, Mai Endo, Daiki Kinou, Noriyuki Hatae, and Tominari Choshi*

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

Abstract

In this study, the synthesis of pyrrolo[2,3-c]quinoline as a common skeleton, is described. The process is based on the thermal electrocyclization of 3-phenylpyrrole containing isocyanate as 2-azahexatriene. Using this approach, the total synthesis of three natural marinoquinolines A, B, and E can be successfully achieved.

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Published online: 11th June, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-930
Synthesis of Nitrogen Heterocycles through Cyanative Cyclization and Cycloaddition Reactions under Transition Metal Catalysis

Shigeru Arai* and Atsushi Nishida

*Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan

Abstract

Synthesis of cyano-functionalized nitrogen heterocycles under palladium, nickel, and cobalt catalysis is described. These transformations include the activation of C-C multiple bonds to give the functionalized pyrrolidines and their related compounds. The palladium-catalyzed reactions promote nucleophilic cyanation to non-activated terminal alkynes. Nickel catalysis enables to install H and CN functionalities into allenes with regio- and stereoselective manner. In the case of cobalt-catalyzed hydrocyanation, hydroacylation and hydroarylation, simple olefins as well as enamines are suitable substrates to construct highly functionalized hetero- and carbocycles. The applications of the above methodologies for the synthesis of alkaloids and related compounds are also described.

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Published online: 2nd June, 2020

Communication | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)10
Studies on Rotational Stability of 2-Aryl-3-(2-Fluorophenyl)Quinazolin-4-One Derivatives

Asumi Iida, Kazuya Saito, Nanami Asada, Yuuki Fujimoto, and Osamu Kitagawa*

*Department of Applied Chemistry, Faculty of Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Kohto-ku, Tokyo 135-8548, Japan

Abstract

The rotational barriers around an N-(2-F)C6H4 bond in 2-aryl-3-(2-fluorophenyl)quinazolin-4-ones considerably lowered (ca. 4 kcal mol-1 lower) in comparison with those of 2-alkyl-3-(2-fluorophenyl)quinazolin-4-ones. The transition state structure estimated by the DFT calculation indicates that the considerable decrease in the rotational barriers in 2-aryl derivatives is caused by the alleviation of the steric repulsion between an ortho-substituent of 2-fluorophenyl group and 2-aryl group.

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Published online: 22nd May, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-20-929
Chemical Syntheses and Biological Studies of Agelastatin A, A Bioactive Marine Heterocycle Gifted from Nature

Takehiko Yoshimitsu*

*Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan

Abstract

Agelastatin A, an alkaloid originally isolated from the marine sponge Agelas dendromorpha, has long been an attractive target of chemical synthesis due to its significant biological activity and unique chemical structure. The synthetic approaches to the agelastatin alkaloid have demonstrated the advances of new methodologies and strategies for accessing a highly functionalized polycyclic nitrogen heterocycle. The present article reviews synthetic endeavors on agelastatin A that have been made by various synthetic chemists as well as biological studies on the natural product and its analogues aimed at the development of medicinal resources.

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Published online: 22nd May, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)13
3-Trifluoromethanesulfonyloxy-4,7-Dihydro-Pyrazolo[1,5-a]Pyridine Via Ring-Closing Metathesis: Synthesis and Transformation to Withasomnine Homologs

Yoshihide Usami,* Yuya Tatsui, Kodai Sumimoto, Ayami Miyamoto, Nanase Koito, Hiroki Yoneyama, and Shinya Harusawa

*Laboratory of Pharmaceutical Organic Chemistry, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan

Abstract

3-Trifluoromethanesulfonyloxy-4,7-dihydropyrazolo[1,5-a]pyridine (9) was successfully synthesized from the starting material, pyrazole, via a sequence of reactions containing ring-closing metathesis as a key step. Suzuki-Miyaura coupling of 9 with various arylboronic acids, followed by oxidation or hydrogenation, readily afforded pyrazolo[1,5-a]pyridines (11) or 3-aryl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridines (12), respectively. Compounds 12 were found to be withasomnine homologs

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Published online: 21st May, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)7
Synthesis of 5-H Thiazoles via Thioamide Dianions with Thioformamides: Pyridylmethyl Group on The Nitrogen Atom of Thiazole Promotes The Formation of 5-H Thiazoles

Khurnia Krisna Puji Pamungkas , Shizuka Hattori, Toshifumi Maruyama, Masahiro Ebihara, and Toshiaki Murai*

*Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University , 1-1 Yanagido, Gifu, Gifu 501-1193, Japan

Abstract

The reaction of in situ-generated thioamide dianions having a pyridylmethyl group on the nitrogen atom with thioformamides resulted in the formation of 5-H thiazoles as major products along with 5-N,N-dimethylaminothiazoles. The presence of a pyridylmethyl group plays an important role in the formation of 5-H thiazoles. A wide range of substituents at the 2-position of a thiazole ring tolerated the reaction conditions, and the intramolecular cyclization reaction proceeded smoothly. However, a phenyl substituent at the 4-position of a thiazole ring significantly reduced the yields of 5-H thiazoles.

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Published online: 14th May, 2020

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)9
Synthesis of A Pentacoordinate Germanium Compound Possessing A γ-Lactone And A Dative-Bonding Carboxylic Acid

Hiroki Tanimoto,* Daiki Toumori, Tsumoru Morimoto, and Kiyomi Kakiuchi*

*Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan

Abstract

A pentacoordinate germanium compound consisting of a spirocyclic dilactone-like structure was synthesized. Both radical and oxidation synthetic routes afforded the diphenylgermanium dicarboxylic acid compound. Then, mono-dearylation by acid treatment successfully delivered a hypercoordinate germane product. X-Ray crystallographic analysis revealed that the product adopted trigonal bipyramidal geometry in which a γ-lactone ring and a dative-bonding carboxylic acid moiety were incorporated.

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Published online: 13th May, 2020

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)11
Synthesis of Pyrrolo[1,2-c]Pyrimidines

Easha Narayan, Liangfeng Fu, and Gordon W. Gribble*

*6128 Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, U.S.A.

Abstract

The synthesis of several new pyrrolo[1,2-c]pyrimidines from the base-induced condensation of pyrrolo-2-carbaldehydes with either TosMIC (toluenesulfonylmethyl isocyanide) or ethyl isocyanoacetate is described, along with the preparation of novel bis(pyrrolo[1,2-c]pyrimidines).

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Published online: 13th May, 2020

Short Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)5
Conjugate Addition Reaction of Indole to Protected 2-Amino-1-Nitroethenes Mediated by Silica Gel

Kenichi Murai,* Shuji Miyazaki, and Hiromichi Fujioka*

*Graduate School of Pharmaceutical Science, Osaka University, 1-6 Yamadaoka, Suita, Osaka 560-0871, Japan

Abstract

We have developed a silica-gel-mediated route for the conjugate addition of indole to protected 2-amino-1-nitroethenes for the synthesis of 1-indolyl-1,2-ethanediamines. This is the first demonstration of indole as the nucleophile for addition to protected 2-amino-1-nitroethenes.

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Published online: 12th May, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)8
Concise Preparation and Biological Evaluations of 9-cis-Retinoic Acid Analogues Having an Aromatic Ring

Takashi Okitsu,* Kinya Iwatsuka, Kimie Nakagawa, Toshio Okano, and Akimori Wada*

*Faculty of Pharmaceutical Science, Kobe Pharmaceutical University, 4-19-1, Motoyamakita, Higashinada, Kobe 658-8558, Japan

Abstract

A series of 9-cis-retinoic acid analogues having an aromatic ring were prepared in only two steps, and were evaluated for transcriptional activities with retinoic acid response element (RARE) and retinoid X response element (RXRE). Among them, compound 6c, bearing a 2-naphthyl substituent, exhibited the highest transcriptional activity with RXR selectivity.

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Published online: 8th May, 2020

Review | Regular issue | Prepress
DOI: 10.3987/REV-19-924
New and Practical Applications of Functionalized Cyclotriphosphazene Core-Based Materials

Manabu Kuroboshi* and Hideo Tanaka

*Graduate School of Natural Science and Technology, Okayama University, Tsushima-naka 3-1-1, Kita-ku, Okayama, 700-7530, Japan.

Abstract

Hexachlorocyclotriphosphazene (HCCP) is a very old compound, and used as a starring material of a variety of cyclotriphosphazene derivatives. Some of them have unique properties, and have been used in not only frame retardants but also functional materials and biomaterials. To develop cyclotriphosphazene derivatives having a desired function, numbers of substituents, regio-, and stereochemistry should be controlled in the reaction between HCCP and nucleophiles. In this review, selectivity in the reaction between HCCP and nucleophiles as well as application of the cyclotriphosphazene derivatives are summarized.

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Published online: 8th May, 2020

Communication | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)6
Synthesis of Lactone-Fused Cyclopropanes by Ring Contractive α-Ketol Rearrangement of Ketal-Fused Cyclobutanones

Kiyosei Takasu,* Koichi Shigenaga, Kazuma Shimoda, Hiroshi Takikawa, and Yousuke Yamaoka

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

Abstract

Ring contraction of cyclic silyl ketal-fused cyclobutanones into lactone-fused cyclopropanes under desilylative conditions is described. The reaction affords 1-hydroxy- and 1-amino-1-cyclopropanecarboxylic acid derivatives from cyclobutanone substrates and their imine congeners, respectively.

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Published online: 28th April, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)3
Thermally-Induced Doping of The Regioregular Polythiophene Bearing Alkylene Spacered Benzene Sulfonate Group at The Side Chain

Chihiro Kubota, Daisuke Morita, Keisuke Fujita, Sonoka Yamamoto, Toyoko Suzuki, Kentaro Okano, Masahiro Funahashi, Masaki Horie, and Atsunori Mori*

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

Abstract

Regioregular polythiophene bearing a benzenesulfonate group, which involved an alkylene spacer between thiophene and benzene ring, was synthesized. The obtained polythiophene was shown to improve its conductivity by heating the polymer thin film through the transformation of the ester group into the corresponding sulfonic acid.

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Published online: 17th April, 2020

Paper | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)1
Synthesis of Probe Molecules, 6-(Dimethylamino)-2-Phenylisoindolin-1-Ones, for Mechanistic Studies of Firefly Luciferase Inhibition

Medha J. Gunaratna, Bo Hao, Man Zhang, Madoka Nakagomi, Ai Ito, Takeo Iwamoto, and Duy H. Hua*

*Department of Chemistry, Kansas State University, Manhattan, KS 66506, U.S.A.

Abstract

Firefly luciferase is used in high-throughput screening based on the detection of chemiluminescence. It catalyzes an esterification reaction of luciferin with adenosine 5’-triphosphate (ATP) followed by decarbonylation with oxygen and concomitance of light. Previously, we reported that firefly luciferase also possesses acyl-CoA synthetase activity and catalyzes an aromatic carboxylic acid group of F-53, using ATP, Mg2+ and coenzyme A (CoA), to produce F-53 covalently attached to active-site lysine-529 residue of firefly luciferase through the formation of an amide group. The amidation of lysine-529 resulted in a deactivation of luciferase. In order to probe firefly luciferase inhibition’s mechanism, we synthesized two probe molecules 1 and 2, mimicking F-53. Molecule 1 contains an azido-appended side chain in the aromatic ring of F-53, while 2 possesses an azido and a carboxylic acid group appended side chains. Both synthetic schemes are readily amenable to large-scale syntheses. Molecule 1 was made from 2-allylaniline, which was derived from a thermal-induced aromatic-Claisen rearrangement of N-allylaniline. The azido-appended side chain of 2 was installed from a Horner-Wadsworth-Emmons reaction and the carboxylic acid side chain from a Sonogashira reaction.

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Published online: 16th April, 2020

Communication | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)4
Synthetic Studies on Densanins: Stereoselective Construction of A Pyrrolidine Ring Containing a Quaternary Carbon

Kyosuke Ueda and Satoshi Yokoshima*

*Graduate School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan

Abstract

We disclose our synthetic studies on densanins, which feature the stereoselective cycloaddition of a cycloheptenone and an azomethine ylide to construct a pyrrolidine ring containing a quaternary carbon

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Published online: 16th March, 2020

Communication | Special issue | Prepress
DOI: 10.3987/COM-20-S(K)2
5-Arylidenetetronate as A Versatile Electrophore for Pi-Extended Electron Acceptors

Yuki Hayashi, Yusuke Ishigaki, Jérémy Merad, Takanori Suzuki,* and Maurice Médebielle*

*Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan

Abstract

Bis[4-methoxy-5-methylenefuran-2(5H)-one]-type electron acceptors with anthracene-9,10-diyl and thiophene-2,5-diyl spacer were prepared by one-pot condensation of methyl tetronate with the corresponding dialdehydes. They undergo reversible electrochemical reduction, thus showing the potential utility of 5-arylidenetetronate as an electrophore for developing novel electron acceptors.

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58 data found. 31 - 58 listedFirst Previous