Special Issue

Tohru Fukuyama's Special Issues, Vol. 99, No. 2, 2019

52 data found. 31 - 52 listedFirst Previous
Paper | Special issue | Vol 99, No. 2, 2019, pp. 1170 - 1182
Published online: 8th January, 2019
DOI: 10.3987/COM-18-S(F)89
Further Studies on the Gold-Catalyzed Oxidative Domino Cyclization/Cycloaddition to Give Polyfunctional Tetracycles

Tobias Groß, Korany A. Ali, Anne Jäger, and Peter Metz*

*Faculty of Chemistry and Food Chemistry, Organic Chemistry I, Technische Universität Dresden, Bergstraße 66, 01069 Dresden, Germany

Abstract

Enyne aldehydes and ketones with ester and ether functions in the tether between the reactive functional groups were subjected to a gold(III)-catalyzed domino process in the presence of a pyridine N-oxide as external oxygen donor. The resulting tetracyclic ketoethers were formed in high yields under mild conditions and with excellent induced diastereoselectivity for substrates featuring a stereogenic center within the enyne tether.

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Paper | Special issue | Vol 99, No. 2, 2019, pp. 1183 - 1195
Published online: 15th February, 2019
DOI: 10.3987/COM-18-S(F)94
Synthesis of a Poly-Heterocyclic Tetra-Substituted Alkene via a Palladium-Catalyzed Four-Fold Domino Reaction for the Design of Polymeric Molecular Switches

Taukeer A. Khan and Lutz F. Tietze*

*Institute of Organic and Biomolecular Chemistry, University of Goettingen, Tammannstrasse 2, 37077 Goettingen, Germany

Abstract

A facile synthesis of a complex poly-heterocyclic tetrasubstituted alkene 4 with intrinsic helical chirality containing two acrylate moieties suitable for polymerization is described. Compound 4 can act as a molecular switch and was prepared via a palladium-catalyzed four-fold domino reaction including two Sonogashira reactions and two domino-carbopalladation/CH-activation reactions.

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Paper | Special issue | Vol 99, No. 2, 2019, pp. 1196 - 1216
Published online: 20th February, 2019
DOI: 10.3987/COM-18-S(F)95
Construction of Pinpoint-Fluorinated Benzothiophene Frameworks Using Palladium-Catalyzed Cyclization of o-(Fluorovinyl)phenyl-Substituted Thiophenes

Kohei Fuchibe, Nobushige Tsuda, Kento Shigeno, and Junji Ichikawa*

*Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki 305-8571, Japan

Abstract

o-(2,2-Difluorovinyl)phenyl- or o-(1,2,2-trifluorovinyl)phenyl-substituted thiophenes underwent palladium(II)-catalyzed Friedel–Crafts-type cyclization on the fluorovinyl moieties to construct regioselectively monofluorinated or difluorinated benzothiophene frameworks (pinpoint-fluorinated naphtho[b]thiophenes). The cyclization of less nucleophilic 2-substituted thiophenes was effectively promoted by the addition of a CuOTf complex. Cyclization was also conducted in a tandem process, which facilitated the rapid synthesis of higher-order pinpoint-fluorinated PAHs (polycyclic aromatic hydrocarbons) bearing thiophene rings. Furthermore, cyclization was applied to the corresponding furan systems, which led to pinpoint-fluorinated naphtho[b]furans.

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Paper | Special issue | Vol 99, No. 2, 2019, pp. 1217 - 1225
Published online: 22nd January, 2019
DOI: 10.3987/COM-18-S(F)96
A De Novo Asymmetric Synthesis of Phomopsolide E: A Practical Conversion from Phomopsolide D

Joel M. Harris, Miaosheng Li, and George A. O'Doherty*

*Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA.

Abstract

A practical three-step synthesis of phomopsolide E has been developed from a synthetic sample of phomopsolide D in three steps at 62% yield. A de novo asymmetric synthesis of phomopsolide D was accomplished in 8 steps from an achiral dienone in 47% yield. The initial asymmetry of phomopsolide E was installed by a Sharpless asymmetric dihydroxylation, whereas, a highly diastereoselective reagent control iterative asymmetric hydrogenation reaction was used to diastereoselectively install the pyranone stereochemistry. The net synthetic effort of phomopsolide E was accomplished in a total 11 steps in 40% overall yield. The route as devised provided for the first-time access to synthetic material for biological analysis and established both the absolute and relative stereochemistry for this natural product.

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Paper | Special issue | Vol 99, No. 2, 2019, pp. 1226 - 1238
Published online: 15th February, 2019
DOI: 10.3987/COM-18-S(F)97
Optimized Synthesis and Solid State Investigations on the Drug Candidate Encenicline Hydrochloride

Gerhard Laus, Sandro Neuner, Ramona Metz, Thomas Müller, Volker Kahlenberg, Thomas Gelbrich, Sven Nerdinger,* Erwin Schreiner, Verena Adamer, Klaus Wurst, and Herwig Schottenberger

*Global Portfolio, Sandoz GmbH, Biochemiestrasse 10, 6250 Kundl, Austria

Abstract

For the production of drug substances a robust, scalable process delivering the active pharmaceutical ingredient (API) in excellent chemical and polymorphic purity is required. For this purpose we developed a novel imidazole-mediated one-pot procedure for the preparation of encenicline hydrochloride monohydrate, which crystallizes directly from the reaction mixture as pure non-hygroscopic polymorph (Form I). Solid state studies revealed a series of additional new physical forms for which crystal structures have been determined by single crystal X-ray diffraction.

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Paper | Special issue | Vol 99, No. 2, 2019, pp. 1239 - 1250
Published online: 1st February, 2019
DOI: 10.3987/COM-18-S(F)98
Stereospecific Ring-Expanding Skeletal Rearrangement of Isoindoline to Tetrahydroisoquinoline via a Sequential Aziridine Ring Formation/Opening

Kenichi Kobayashi,* Ryusei Endo, Yusuke Honma, Emi Kasahara, Haruka Saito, Kosaku Tanaka III, Momoko Suzuki, and Hiroshi Kogen*

*Graduate School of Pharmaceutical Sciences, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan

Abstract

A stereospecific skeletal rearrangement of isoindoline to tetrahydroisoquinoline was developed under Appel reaction conditions using a combination of PPh3 and CCl4. This reaction involves a sequential ring formation/opening of a labile aziridine and enables the construction of a quaternary carbon center, offering a highly useful method for accessing 3,3,4-trisubstituted tetrahydroisoquinolines.

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Paper | Special issue | Vol 99, No. 2, 2019, pp. 1251 - 1275
Published online: 27th February, 2019
DOI: 10.3987/COM-18-S(F)99
Diastereo–/Enantioselective Diels–Alder Synthesis of 14β-Hydroxysteroid Scaffolds: A Combined Experimental and DFT Study

Clovis Peter, Philippe Geoffroy, Takatsugu Murata, Takayuki Tonoi, Isamu Shiina,* and Michel Miesch*

*Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan

Abstract

Natural, non-natural and ent-14β-hydroxyandrostane derivatives closely related to the cardenolide and bufadienolide skeletons were readily available through highly diastereo-/enantioselective Diels–Alder reactions calling for high pressure or Lewis acid activation. Moreover, in the presence of (R)- or (S)-carvone as chiral dienophile, the Diels–Alder reaction took place under chemodivergent parallel kinetic resolution control. Based on experimental and DFT studies, reasonable mechanism insights were postulated to explain the concave/convex and endo/exo selectivities observed for the formation of the different Diels–Alder and Diels–Alder–Michael adducts.

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Paper | Special issue | Vol 99, No. 2, 2019, pp. 1276 - 1303
Published online: 14th February, 2019
DOI: 10.3987/COM-18-S(F)100
Preparation of Tricyclic Analog as CDE Ring Model of Renieramycin Marine Natural Product by Novel Photo-Induced Transformation of 6-Methoxy-1,2,3,4-tetrahydroisoquinoline-5,8-dione

Masashi Yokoya, Shohei Takahashi, and Naoki Saito*

*Graduate School of Pharmaceutical Sciences, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan

Abstract

2-Acetyl-6-[(benzyloxy)methyl]-9-methoxy-8-methyl-11,11a- dihydro-2H-pyrazino[1,2-b]isoquinoline-1,4,7,10(3H,6H)-tetraone (11a) was prepared as the CDE ring model of renieramycins, and its novel photo-induced transformation was demonstrated to construct a 1,3-dioxol ring.

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Paper | Special issue | Vol 99, No. 2, 2019, pp. 1304 - 1314
Published online: 20th February, 2019
DOI: 10.3987/COM-18-S(F)101
1,2-cis-Selective Formation of a Unique Amino-Containing Amino Glycoside by Endocyclic Cleavage Strategy

Shino Manabe* and Yukishige Ito*

*Synthetic Cellular Chemistry Laboratory, RIKEN, Hirosawa, Wako, Saitama 351-0198, Japan

Abstract

2-Acetamido-4-amino-2,4,6-trideoxy-α-D-galactopyranoside (AAT), a unique aminated sugar unit, is often found in zwitterionic polysaccharides. Stereoselective formation of the 1,2-cis linkage of these unique sugar derivatives was achieved by an anomerization reaction based on an endocyclic cleavage process.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1315 - 1321
Published online: 17th December, 2018
DOI: 10.3987/COM-18-S(F)45
Palladium Acetate-Catalyzed One-Pot Synthesis of Mono- and Disubstitued Pyridines

Shunya Mikami and Masahiro Toyota*

*Department of Chemistry, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan

Abstract

A Pd-catalyzed one-pot synthesis of mono- and disubstituted pyridines was developed. The substituted pyridines were obtained from ketones or an aldehyde and 1,3-diaminopropane using a combination of catalytic Pd(OAc)2 and Cu(OAc)2. High-concentration reaction conditions enabled this catalytic reaction to be acid-free.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1322 - 1329
Published online: 26th October, 2018
DOI: 10.3987/COM-18-S(F)47
Formation of an Aluminum Complex of 5-O-Caffeoylquinic Acid with Chiral Molecular Stacking under Vacuolar Condition

Kumi Yoshida,* Daisuke Ito, and Tadao Kondo

*Graduate School of Informatics, Nagoya University, Chikusa, Nagoya 464-8601, Japan

Abstract

5-O-Caffeoylquinic acid (neochlorogenic acid, 5CQ) is an essential co-pigment for blue coloration of hydrangea. 5CQ solubilizes a water insoluble aluminum complex of 3-O-glucosyldelphinidin (Dp3G) to give a water-soluble blue complex, in which both Dp3G and 5CQ chelate a single Al3+ ion. However, its isomer, 3-O-caffeoylquinic acid (chlorogenic acid, 3CQ), has no such effect and does not give blue complex. It was clarified that 5CQ was complexed with Al3+ with a chiral molecular stacking under physiological vacuolar condition as aq. solution at pH 4.0. However, 3CQ did not give such complex with Al3+. The difference in aluminum complexation between the isomers may result from the difference configuration of 5-OH and 3-OH group in quinic acid.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1330 - 1341
Published online: 16th November, 2018
DOI: 10.3987/COM-18-S(F)54
Bimetallic Lewis Acid Template-Mediated Enantioselective Hetero-Diels-Alder Reactions of 4-Siloxy-2,4-pentadienols

Jun Ishihara,* Yuka Ohzono, Kengo Oka, Yasuhiro Urayama, and Susumi Hatakeyama

*Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, 852-8521, Japan

Abstract

Enantioselective hetero-Diels-Alder reactions catalyzed by a bimetallic Lewis acid template are described. The hetero-Diels-Alder reactions of 4-siloxy-2,4-pentadienols and various dienophiles by the chiral H8-BINOL template provide a general entry into the substituted dihydropyrans with good enantioselectivities. This protocol is also applicable to a dihydropirazine formation.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1342 - 1354
Published online: 25th January, 2019
DOI: 10.3987/COM-18-S(F)64
Problem of Regioselectivity in the Amination of 2-Fluoro-5-iodopyridine with Adamantylalkyl Amines

Anton S. Abel, Yury N. Kotovshchikov, Alexei D. Averin,* Olga A. Maloshitskaya, Evgenii N. Savelyev, Boris S. Orlinson, Ivan A. Novakov, and Irina P. Beletskaya

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

Abstract

Cu(I)-Catalyzed and catalyst-free amination of 2-fluoro-5-iodopyridine with adamantylalkyl amines possessing different steric hindrances at amino group was investigated to obtain corresponding 5-amino-2-fluoro- and 2-amino-5-iodopyridines. The competition between catalytic substitution of iodine and non-catalytic substitution of fluorine was shown to take place. The catalytic system CuI/2-(isobutyryl)cyclohexanone in DMF provided yields of 5-amino-2-fluoropyridines up to 58% with stoichiometric ratio of the reagents and up to 98% with two equiv. of amines. The non-catalytic amination of 2-fluoro-5-iodopyridine provided the yields of 2-amino-5-iodopyridines up to 97%.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1355 - 1360
Published online: 17th December, 2018
DOI: 10.3987/COM-18-S(F)67
Preparation and Optical and Electrochemical Properties of Phthalocyanine with Four Bis(carbomethoxy)tetrathiafulvalene Units

Takeshi Kimura* and Tadafumi Chiba

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

Abstract

α-Octaoctylphthalocyaninato Ni(II) with four bis(carbomethoxy)tetrathiafulvalene units was prepared from β-tetrakis(o-xylylenedithio)-α-octaoctyl-phthalocyaninato Ni(II) via C-S bond cleavage, carbonylation, and condensation with 4,5-bis(carbomethoxy)-1,3-dithiol-2-one. The structure of the product was determined by NMR and MALDI-TOF-MS and the electrochemical and optical properties were examined by cyclic voltammetry, UV-vis spectra, and ESR spectrum.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1361 - 1365
Published online: 18th December, 2018
DOI: 10.3987/COM-18-S(F)69
Efficient Synthesis of Benzofuran Fused 1-Azaazulene

Hiroyuki Fujii,* Yusuke Hironaka, and Noritaka Abe

*Science Research Center, Yamaguchi University, Yamaguchi 753-8512, Japan

Abstract

The synthesis of benzofuran fused 1-azaazulene (cyclohepta[d]benzo[4,5]furano[2,3-b]pyrrole) (4) was achieved by one pot reaction of 2-chloro-1-azaazulene (1) with 2-iodophenol (2) under the conditions in the presence of Pd(OAc)2 and without using a ligand.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1366 - 1387
Published online: 3rd December, 2018
DOI: 10.3987/COM-18-S(F)76
Divergent Synthesis of Photoaffinity Probe Candidates by Click Reactions of Azido-Substituted Aryltrifluoromethyldiazirines

Kenji Watanabe, Junpei Tsuda, Hidenori Ochiai, Takashi Niwa, and Takamitsu Hosoya*

*Laboratory of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan

Abstract

Two types of azido-substituted aryltrifluoromethyldiazirine units have been designed and prepared for the divergent synthesis of photoaffinity probe (PAP) candidates. Using these azides, various aryltrifluoromethyldiazirine derivatives have been rendered easily synthesizable by several click reactions, as well as the Staudinger reduction affording the corresponding aniline. The triazole-conjugated aryltrifluoromethyldiazirine derivatives prepared in this study showed normal photoreactivity compared with those reported previously. These results indicate the utility of these azido-substituted aryltrifluoromethyldiazirine units for development of PAPs for target identification of bioactive compounds.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1388 - 1397
Published online: 25th February, 2019
DOI: 10.3987/COM-18-S(F)83
Study toward an Asymmetric and Catalytic Synthesis of Koumine

David Reyes Loya, Jacques Maddaluno, and Michaël De Paolis*

*Normandie Université, UNIROUEN, INSA de Rouen, CNRS, Laboratoire COBRA (UMR 6014 & FR 3038), 76000 Rouen, France

Abstract

A synthetic study of koumine, a natural product with a densely functionalized and inspiring heterocyclic skeleton, was conducted by exploring a strategy of desymmetrization of 1,3-cyclohexanedione by an intramolecular vinylation reaction of an enolate under palladium catalysis to give a strained bridgehead 1,3-cyclohexanedione scaffold. In the course of the study, a domino ring expansion was discovered and developed.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1398 - 1411
Published online: 13th February, 2019
DOI: 10.3987/COM-18-S(F)87
Asymmetric Synthesis of t-Butyl 3-Alkyl-oxindole-3-carboxylates via Chiral Phosphoric Acid-Catalyzed Desymmetrization of Di-t-butyl 2-Alkyl-2-(2-aminophenyl)malonates

Kyoji Ishida, Masahiro Shimizu, Yu-suke Yamai, Itaru Natsutani, Shinichi Uesato, Yasuo Nagaoka, and Takaaki Sumiyoshi*

*Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Yamate-cho 3-3-35, Suita, Osaka, 564-8680, Japan

Abstract

We describe the asymmetric desymmetrization of di-t-butyl 2-alkyl-2-(2-aminophenyl)malonates to prepare enantioenriched t-butyl 3-alkyl-oxindole-3-carboxylates using (S)-TRIP, a chiral phosphoric acid. Optimization study increased the enantioselectivity up to 66% ee.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1412 - 1422
Published online: 7th January, 2019
DOI: 10.3987/COM-18-S(F)88
Synthesis of Indolo[1,2-a]indole Derivatives by Cationic Au(I)-Catalyzed exo-Selective Cycloisomerization and Their Photophysical Properties

Madhurima Hazra, Daisuke Inoue, Mamoru Ito, Kyalo Stephen Kanyiva, and Takanori Shibata*

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

Abstract

Cationic Au(I)-catalyzed intramolecular cycloisomerization of N-(2-alkynylphenyl)indoles proceeded efficiently in exo-selective manner, and (Z)-10-(arylidene)indolo[1,2-a]indole derivatives were obtained in moderate to high yields. Their photophysical properties were also measured.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1423 - 1433
Published online: 5th February, 2019
DOI: 10.3987/COM-18-S(F)90
A Novel Route to (R)-2-(3-Chlorophenyl)propan-1-amine, a Key Intermediate for the Synthesis of Lorcaserin

Ivana Gazic Smilovic, Sven Nerdinger,* Sandro Neuner, Herwig Schottenberger, Thomas Gelbrich, and Klaus Wurst

*Global Portfolio, Sandoz GmbH, Biochemiestrasse 10, 6250 Kundl, Austria

Abstract

A new and efficient three-step synthesis of (R)-2-(3-chlorophenyl)propan-1-amine is reported, which serves as an intermediate in the synthesis of the antiobesity drug lorcaserin. The key step is a chiral resolution due to the formation of a salt with l-(-)-3-phenyllactic acid. The structure of the relevant salt phase is reported.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1434 - 1443
Published online: 18th February, 2019
DOI: 10.3987/COM-18-S(F)102
Synthesis of Di(3-thienyl)benzoporphyrin

Tetsuo Okujima,* Kota Muramatsu, Shigeki Mori, Masayoshi Takase, and Hidemitsu Uno

*Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan

Abstract

We have successfully synthesized 2,3-di(3-thienyl)benzo[b]porphyrin based on retro DielsAlder reaction of bicyclo[2.2.2]octadiene(BCOD)-fused porphyrin and investigated its photoisomerization reaction.

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Short Paper | Special issue | Vol 99, No. 2, 2019, pp. 1444 - 1451
Published online: 14th February, 2019
DOI: 10.3987/COM-18-S(F)103
Synthesis of Furan-Fused Silole and Phosphole by One-Pot Halogen Dance/Homocoupling of Bromofurfural Derivative

Kentaro Okano,* Yuki Murase, and Atsunori Mori

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

Abstract

Synthesis of a furan-fused silole and phosphole was achieved through a one-pot halogen dance/homocoupling of a bromofurfural derivative followed by the formation of the silole and phosphole skeleton.

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