MISC - 好光　健彦

A commentary on‘Classic Addition Reaction Gets A Makeover’ in Science & Technology, News of The Week in Chemical & Engineering News

Takehiko Yoshimitsu

Chemical & Engineering News   93 ( 3 )   2015年

　詳細を見る

researchmap

Enantiospecific Synthesis and Cytotoxicity Evaluation of Ligudentatol: A Programmed Aromatization Approach to the 2,3,4-Trisubstituted Phenolic Motif via Visible-Light-Mediated Group Transfer Radical Cyclization

Gamal A. I. Moustafa, Hiroshi Suizu, Hiroshi Aoyama, Masayoshi Arai, Shuji Akai, Takehiko Yoshimitsu

CHEMISTRY-AN ASIAN JOURNAL   9 ( 6 )   1506 - 1510   2014年6月

　詳細を見る

記述言語：英語   出版者・発行元：WILEY-V C H VERLAG GMBH  

A facile enantiospecific approach to (+)-ligudentatol (1) and (-)-ligudentatol (ent-1) is reported. The approach features the construction of a trisubstituted phenolic motif fused to a chiral aliphatic ring by a sequence of visible-light-mediated radical seleno transfer cyclization, bromination, concomitant selenoxide elimination-dehydrobromination, and demethoxycarbonylation, namely, a programmed aromatization. Biological evaluation of the enantiomers of ligudentatol obtained by the present route revealed for the first time their cytotoxicity towards various cancer cell lines.

DOI： 10.1002/asia.201400110

Web of Science

researchmap

Endeavors to Access Molecular Complexity: Strategic Use of Free Radicals in Natural Product Synthesis

Takehiko Yoshimitsu

CHEMICAL RECORD   14 ( 2 )   268 - 279   2014年4月

　詳細を見る

記述言語：英語   出版者・発行元：WILEY-V C H VERLAG GMBH  

Free radicals, which in the past were considered unruly chemical species, have become manageable and indispensable for synthetic organic chemistry. The unique nature of free radicals has allowed practitioners in organic synthesis to design flexible approaches to produce various materials ranging from small molecules to polymers. The present Personal Account describes the author's endeavors to create molecular complexity by the strategic use of free radicals, with an emphasis on the synthesis of bioactive natural products.

DOI： 10.1002/tcr.201300024

Web of Science

researchmap

A new route to platencin via decarboxylative radical cyclization

Gamal A. I. Moustafa, Yuki Saku, Hiroshi Aoyama, Takehiko Yoshimitsu

CHEMICAL COMMUNICATIONS   50 ( 99 )   15706 - 15709   2014年

　詳細を見る

記述言語：英語   出版者・発行元：ROYAL SOC CHEMISTRY  

A new approach to platencin, a potent antibiotic isolated from Streptomyces platensis, has been established. The highly congested tricyclic core of the natural product was successfully constructed by decarboxylative radical cyclization of an alkynyl silyl ester with Pb(OAc)(4) in the presence of pyridine in refluxing 1,4-dioxane. The key decarboxylation, which likely takes place via lead(IV) esterification followed by carbon-centered radical generation and subsequent capture of the radical with a triple bond, allows the rapid construction of the twisted polycyclic system.

DOI： 10.1039/c4cc07316a

Web of Science

researchmap

An integrated approach to the discovery of potent agelastatin A analogues for brain tumors: chemical synthesis and biological, physicochemical and CNS pharmacokinetic analyses 国際共著 国際誌

Zhimin Li, Daisuke Shigeoka, Thomas R. Caulfield, Takashi Kawachi, Yushi Qiu, Takuma Kamon, Masayoshi Arai, Han W. Tun, Takehiko Yoshimitsu

MEDCHEMCOMM   4 ( 7 )   1093 - 1098   2013年7月

　詳細を見る

記述言語：英語   出版者・発行元：ROYAL SOC CHEMISTRY  

(-)-Agelastatin A (AA), isolated from the coral sea axinellid sponge Agelas dendromorpha, has shown a high antineoplastic activity. We have synthesized eighteen AA analogues and analyzed their cytotoxicities towards three cancer cell lines. By the structure-activity relationship (SAR) study, we identified three novel analogues with higher or comparable cytotoxic activities to AA. They were subjected to chemoinformatic analysis, which revealed physicochemical properties favoring excellent central nervous system (CNS) penetration. CNS pharmacokinetic analysis in murine models validated the chemoinformatic prediction and revealed that these analogues indeed had better CNS penetration than AA. These novel potent AA analogues deserve further evaluation for therapeutic use against cancers, particularly primary and secondary brain tumors.

DOI： 10.1039/c3md00094j

Web of Science

researchmap

Formal synthesis of (-)-agelastatin A: an iron(II)-mediated cyclization strategy

Daisuke Shigeoka, Takuma Kamon, Takehiko Yoshimitsu

BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY   9   860 - 865   2013年5月

　詳細を見る

記述言語：英語   出版者・発行元：BEILSTEIN-INSTITUT  

An iron(II)-mediated aminohalogenation of a cyclopentenyl N-tosyloxycarbamate provided new access to the key intermediate for the synthesis of (-)-agelastatin A (AA, 1), a potent antiproliferative alkaloid. The present synthetic endeavour offered an insight into the mechanism underlying the iron(II)-mediated aminohalogenation of N-tosyloxycarbamate, in which the radical properties of the N-iron intermediates in the redox states were operative.

DOI： 10.3762/bjoc.9.99

Web of Science

researchmap

Structure-activity relationships of hybrid annonaceous acetogenins: Powerful growth inhibitory effects of their connecting groups between heterocycle and hydrophobic carbon chain bearing THF ring on human cancer cell lines

Naoto Kojima, Tetsuya Fushimi, Takahiro Tatsukawa, Takehiko Yoshimitsu, Tetsuaki Tanaka, Takao Yamori, Shingo Dan, Hiroki Iwasaki, Masayuki Yamashita

EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY   63   833 - 839   2013年5月

　詳細を見る

記述言語：英語   出版者・発行元：ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER  

Five novel hybrid molecules of annonaceous acetogenins and insecticides targeting mitochondrial complex I were synthesized and their growth inhibitory activities against 39 human cancer cell lines were investigated. It was revealed that the connecting group between the N-methylpyrazole part and the hydrophobic alkyl chain bearing the THF ring influenced their biological activities significantly. Amide-connected analog 2, in particular, showed selective and very potent activity (<10 nM) against some cancer cell lines. (C) 2013 Elsevier Masson SAS. All rights reserved.

DOI： 10.1016/j.ejmech.2013.03.009

Web of Science

researchmap

Potent Growth Inhibitory Activity of (±)-Platencin towards Multi-Drug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis

Moustafa, G. A. I, Nojima, S, Yamano, Y, Aono, A, Arai, M, Mitarai, S, Tanaka, T, Yoshimitsu, T

Med. Chem. Commun.   4 ( 4 )   720 - 723   2013年4月

　詳細を見る

記述言語：英語  

DOI： 10.1039/c3md00016h

Web of Science

researchmap

Dichlorination of olefins with NCS/Ph3P

Yasumasa Kamada, Yuta Kitamura, Tetsuaki Tanaka, Takehiko Yoshimitsu

ORGANIC & BIOMOLECULAR CHEMISTRY   11 ( 10 )   1598 - 1601   2013年

　詳細を見る

記述言語：英語   出版者・発行元：ROYAL SOC CHEMISTRY  

A 2 : 1 mixture of NCS and Ph3P successfully promoted the anti-dichlorination of olefins to provide corresponding dichlorides, serving as a molecular chlorine surrogate generated in situ.

DOI： 10.1039/c3ob27345h

Web of Science

researchmap

Double C-H Functionalization in Sequential Order: Direct Synthesis of Polycyclic Compounds by a Palladium-Catalyzed C-H Alkenylation-Arylation Cascade

Hiroaki Ohno, Mutsumi Iuchi, Naoto Kojima, Takehiko Yoshimitsu, Nobutaka Fujii, Tetsuaki Tanaka

CHEMISTRY-A EUROPEAN JOURNAL   18 ( 17 )   5352 - 5360   2012年4月

　詳細を見る

記述言語：英語   出版者・発行元：WILEY-V C H VERLAG GMBH  

Palladium-catalyzed cascade C?H alkenylation and arylation provides convenient access to polycyclic aromatic compounds. Treatment of 3-bromoaniline derivatives bearing a bromocinnamyl group on the nitrogen atom with a catalytic amount of [Pd(OAc)2] and PCy3 center dot HBF4 in the presence of Cs2CO3 in dioxane affords naphthalene-fused indole derivatives in good yields. This double cyclization reaction is also applicable to heterocyclic substrates, giving fused indoles containing a heteroaromatic ring such as dibenzofuran, dibenzothiophene, carbazole, indole, or benzofuran through heterocyclic C-H arylation. When using a 2,6-unsubstituted aniline derivative, the first C-H arylation preferentially proceeds at the more hindered position of the aniline ring.

DOI： 10.1002/chem.201103819

Web of Science

researchmap

Pharmacokinetics of Agelastatin A in the central nervous system 国際共著 国際誌

Zhimin Li, Takuma Kamon, David A. Personett, Thomas Caulfield, John A. Copland, Takehiko Yoshimitsu, Han W. Tun

MEDCHEMCOMM   3 ( 2 )   233 - 237   2012年2月

　詳細を見る

記述言語：英語   出版者・発行元：ROYAL SOC CHEMISTRY  

Agelastatin A (AA) is an anti-neoplastic agent with anti-osteopontin (OPN) activity. Brain tumors often express OPN significantly. A comprehensive chemoinformatic analysis followed by in vivo pharmacokinetic evaluations in mice is performed. CNS penetration of AA is about 10%. AA should be further tested for activity against brain tumors.

DOI： 10.1039/c1md00240f

Web of Science

researchmap

Stereoselective α-Quaternization of 3-Methoxycycloalk-2-enones via 1,4-Diastereoinduction of Alkoxy Dienolates

Moustafa, G. A. I, Kamada, Y, Tanaka, T, Yoshimitsu, T

J. Org. Chem.   77 ( 2 )   1202 - 1207   2012年1月

　詳細を見る

記述言語：英語  

DOI： 10.1021/jo2022789

Web of Science

researchmap

Intramolecular iron(II)-catalyzed aminobromination of allyl N-tosyloxycarbamates

Takuma Kamon, Daisuke Shigeoka, Tetsuaki Tanaka, Takehiko Yoshimitsu

ORGANIC & BIOMOLECULAR CHEMISTRY   10 ( 12 )   2363 - 2365   2012年

　詳細を見る

記述言語：英語   出版者・発行元：ROYAL SOC CHEMISTRY  

Allyl N-tosyloxycarbamates are found to be catalytically transformed into beta-brominated oxazolidinones with FeBr2/n-Bu4NBr in t-BuOH.

DOI： 10.1039/c2ob07190h

Web of Science

researchmap

Stereoconvergent route to chiral cyclohexenone building blocks: formal synthesis of (-)-dysidiolide

Gamal A. I. Moustafa, Yasumasa Kamada, Tetsuaki Tanaka, Takehiko Yoshimitsu

ORGANIC & BIOMOLECULAR CHEMISTRY   10 ( 43 )   8609 - 8615   2012年

　詳細を見る

記述言語：英語   出版者・発行元：ROYAL SOC CHEMISTRY  

A stereoconvergent access to chiral carbocyclic building blocks is reported. 6-(3'-Hydroxy-4'-methylpent-4'-enyl)-3-methoxy cyclohex-2-enone (1) that consists of four stereoisomers, i.e., racemic ca. 1:1 diastereomers, is converted to enantiomerically pure carbocycles through a combination of regioselective catalytic asymmetric reduction and alkylative remote stereoinduction. The present stereoconvergent strategy has allowed the formal synthesis of bioactive (-)-dysidiolide.

DOI： 10.1039/c2ob26532j

Web of Science

researchmap

Design and synthesis of C35-fluorinated solamins and their growth inhibitory activities against human cancer cell lines

Naoto Kojima, Yuki Suga, Hiromi Hayashi, Takao Yamori, Takehiko Yoshimitsu, Tetsuaki Tanaka

BIOORGANIC & MEDICINAL CHEMISTRY LETTERS   21 ( 19 )   5745 - 5749   2011年10月

　詳細を見る

記述言語：英語   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

The convergent synthesis of C35-fluorinated analogues of solamin, a mono-THF Annonaceous acetogenin, has been achieved by the Sonogashira coupling of the THF ring fragment and the fluorinated gamma-lactone fragment. It was revealed that the number of fluorine atoms on the gamma-lactone moiety affects the growth inhibitory activities against human cancer cell lines. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.bmcl.2011.08.011

Web of Science

researchmap

Total Synthesis of (±)-Platencin

Yoshimitsu, T, Nojima, S, Hashimoto, M, Tanaka, T

Org. Lett.   13 ( 14 )   3698 - 3701   2011年7月

　詳細を見る

記述言語：英語  

DOI： 10.1021/ol2013439

Web of Science

researchmap

Total Synthesis of (±)-Kainic Acid: A Photochemical C–H Carbamoylation Approach

Kamon, T, Irifune, Y, Tanaka, T, Yoshimitsu, T

Org. Lett.   13 ( 10 )   2674 - 2677   2011年5月

　詳細を見る

記述言語：英語  

DOI： 10.1021/ol200772f

Web of Science

researchmap

Asymmetric Total Synthesis of (+)-Danicalipin A

Takehiko Yoshimitsu, Ryo Nakatani, Akihiro Kobayashi, Tetsuaki Tanaka

ORGANIC LETTERS   13 ( 5 )   908 - 911   2011年3月

　詳細を見る

記述言語：英語   出版者・発行元：AMER CHEMICAL SOC  

A convergent asymmetric total synthesis of (+)-danicalipin A is accomplished, in which two chlorinated fragments are stereoselectively joined by 1,3-dipolar coupling, leading to the confirmation of the absolute configuration of the natural product.

DOI： 10.1021/ol1029518

Web of Science

researchmap

Convergent synthesis of fluorescence-labeled probes of Annonaceous acetogenins and visualization of their cell distribution

Naoto Kojima, Takekuni Morioka, Daisuke Urabe, Masahiro Yano, Yuki Suga, Naoyoshi Maezaki, Ayako Ohashi-Kobayashi, Yasuyuki Fujimoto, Masatomo Maeda, Takao Yamori, Takehiko Yoshimitsu, Tetsuaki Tanaka

BIOORGANIC & MEDICINAL CHEMISTRY   18 ( 24 )   8630 - 8641   2010年12月

　詳細を見る

記述言語：英語   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

The convergent synthesis of fluorescence-labeled solamin, an antitumor Annonaceous acetogenin, was accomplished by two asymmetric alkynylations of 2,5-diformyl tetrahydrofuran with an alkyne tagged with fluorescent groups and another alkyne with an alpha,beta-unsaturated gamma-lactone. Assay for the growth inhibitory activity against human cancer cell lines revealed that the probe with the fluorescent groups at the end of the hydrocarbon chain may have the same mode of action as natural acetogenins. The merged fluorescence of dansyl-labeled solamin and MitoTracker Red suggests that Annonaceous acetogenins localize in the mitochondria. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.bmc.2010.10.004

Web of Science

researchmap

Asymmetric Total Synthesis of (+)-Hexachlorosulfolipid, a Cytotoxin Isolated from Adriatic Mussels

Takehiko Yoshimitsu, Naoya Fukumoto, Ryo Nakatani, Naoto Kojima, Tetsuaki Tanaka

JOURNAL OF ORGANIC CHEMISTRY   75 ( 16 )   5425 - 5437   2010年8月

　詳細を見る

記述言語：英語   出版者・発行元：AMER CHEMICAL SOC  

The enantioselective total synthesis of (+)-hexachlorosulfolipid, a cytotoxin found in the Adriatic mussel Mytilus galloprovincialis, is described. The unique chlorinated hydrocarbon motif of the lipid is successfully furnished by a series of dichlorination reactions of chiral epoxides with chlorophosphonium reagent generated in situ from Ph(3)P/NCS. The present total synthesis has allowed the confirmation of the absolute configuration of the natural cytotoxic (+)-hexachlorosulfolipid originally proposed by Fattorusso, Ciminiello, and co-workers.

DOI： 10.1021/jo100534d

Web of Science

researchmap