Papers - DANJO Hiroshi
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Preparation of spiroborate supramolecular and peapod polymers containing photoluminescent ruthenium(II) complex Invited Reviewed
Wako Matsumoto, Muneyuki Naito, Hiroshi Danjo
RSC Advance 13 25002 - 25006 2023.8
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Preparation of tricationic tris(pyridylpalladium(II)) metallacyclophane as an anion receptor Reviewed
Hiroshi Danjo, Kohei Asai, Tomoya Tanaka, Daiki Ono, Masatoshi Kawahata, Satoshi Iwatsuki
Chemical Communications 58 2196 - 2199 2022.1
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Preparation of cage-shaped hexakis(spiroborate)s Reviewed
Hiroshi Danjo, Yuhki Masuda, Yuki Kidena, Masatoshi Kawahata, Kazuaki Ohara, Kentaro Yamaguchi
Organic & Biomolecular Chemistry 18 ( 18 ) 3717 - 3723 2020.5
Joint Work
Authorship：Lead author, Corresponding author Publisher：Royal Society of Chemistry (RSC)
<p>Direct construction of anionic hexakis(spiroborate) prismatic cages was realized by the reaction of hexahydroxytriphenylene, bis(dihydroxynaphthalene)s, and boric acid.</p>
DOI： 10.1039/d0ob00518e
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Characteristic Hydrogen Bonding Observed in the Crystals of Aromatic Sulfonamides: 1D Chain Assembly of Molecules and Chiral Discrimination on Crystallization Reviewed
Shoko Kikkawa, Hyuma Masu, Kosuke Katagiri, Misaki Okayasu, Kentaro Yamaguchi, Hiroshi Danjo, Masatoshi Kawahata, Masahide Tominaga, Yoshihisa Sei, Hidemasa Hikawa, Isao Azumaya
Cryst. Growth Des. 19 ( 19 ) 2936 - 2946 2019.4
Joint Work
Copyright © 2019 American Chemical Society. N-Phenylbenzenesulfonamides exist preferentially in (+)- or (-)-synclinal conformations, which place the aromatic rings at both ends in the same direction with a twist. We have systematically analyzed the crystal structure of secondary aromatic sulfonamides bearing methyl, ethyl, and/or methoxy groups on the benzene rings. Intermolecular hydrogen bonding between the sulfonamide protons and sulfonyl oxygens was observed in 81 out of 85 crystals. The intermolecular hydrogen-bonding patterns could be classified into four types, i.e. Dimeric, Zigzag, Helical, and Straight patterns, with retention of the synclinal conformation of the sulfonamide moiety. We investigated the relationship between the hydrogen-bonding pattern and the proportion of the compounds that show chiral crystallization. On the basis of our classification of the intermolecular hydrogen bonds of aromatic sulfonamides, the crystals with Dimeric and Zigzag patterns, which both have enantiomeric synclinal conformers, intrinsically become achiral, except for kryptoracemates. In contrast, a high proportion of compounds with Helical or Straight patterns in the crystals showed chiral crystallization. Our classification is useful for discussion regarding the chirality of molecular assemblies, on the basis of the conformational chirality of the molecules in the crystal.
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Construction and structural analysis of mono- and heterobimetallic bis(titanate) molecular cages Reviewed
Toshi Nakagawa, Hiroshi Danjo, Masatoshi Kawahata, Kentaro Yamaguchi
Tetrahedron 75 ( 75 ) 315 - 323 2018.12
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Proton-Induced Assembly-Disassembly Modulation of Spiroborate Twin-Bowl Polymers Bearing Pyridyl Groups Reviewed
Hiroshi Danjo, Masahiro Hamaguchi, Kohei Asai, Mizuki Nakatani, Hiroko Kawanishi, Masatoshi Kawahata, Kentaro Yamaguchi
MACROMOLECULES 50 ( 50 ) 8028 - 8032 2017.9
Joint Work
Authorship：Lead author, Corresponding author Publisher：AMER CHEMICAL SOC
Twin-bowl-shaped tris-(spiroborate) cyclophanes bearing pyridyl groups have been prepared for the construction of proton-responsive supramolecular polymers. Preparation of the pyridyl twin bowls was carried out by the reaction of 6,6'-(3-pyri dyl)-2,2',3,3'-tetrahydroxy- 1, 1'-binaphthyls and an equimolar amount of boric acid in N,N-dimethylformamide in self-organization manner, as previously reported. The reversible acid/base response of the pyridyl twin bowls was evaluated by the addition of hydrochloric acid and aqueous sodium hydroxide. The assembly disassembly modulation of the supramolecular polymers composed of pyridyl twin bowls and the tricationic iridium-(III) complex was also examined. Dissociation of the supramolecular polymers occurred by the addition of hydrochloric acid, and its reconstruction was realized by the addition of aqueous sodium hydroxide. The opposite behavior was observed when the dianionic palladium-(II) complex was employed as a guest. The addition of acid led to the formation of the aggregate that was dissociated by the addition of base.
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Preparation of Peapod Polymer via the Supramolecular Chain Formation by Tris(spiroborate) Twin Bowl Reviewed
Hiroshi Danjo, Toshi Nakagawa, Akio Morii, Yusuke Muraki, Koichi Sudoh
ACS MACRO LETTERS 6 ( 6 ) 62 - 65 2017.1
Joint Work
Authorship：Lead author, Corresponding author Publisher：AMER CHEMICAL SOC
Successive guest-containing tubular polymer was prepared by the olefin metathesis polymerization of tris(spiroborate) twin bowl after the formation of supra molecular polymer. The cationic iridium(III) complexes were topologically fixed inside the polymer to form a peapod-like structure. The polymer was evaluated by SEC, ICP-AES, and DLS analyses, and string-like structures were found in the AFM observation of the peapod polymer.
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Coordination structure and extraction behavior of a silver ion with N-substituted-9-aza-3,6,12,15-tetrathiaheptadecanes: significant effect of Ph-C-N framework on the extractability Reviewed
Satoshi Iwatsuki, Atsushi Ichiyama, Syogo Tanooka, Mari Toyama, Kosuke Katagiri, Masatoshi Kawahata, Kentaro Yamaguchi, Hiroshi Danjo, Kenji Chayama
DALTON TRANSACTIONS 45 ( 45 ) 12548 - 12558 2016.7
Joint Work
Publisher：ROYAL SOC CHEMISTRY
N-Substituted-9-aza-3,6,12,15-tetrathiaheptadecanes having Ph-C-N frameworks (N-R-ATH; R = benzyl (N-Bn-ATH), 4-nitrobenzyl (N-NO2Bn-ATH), and diphenylmethyl (N-Ph2CH-ATH)) were synthesized, and their Ag(I) complexes were structurally characterized. X-Ray crystal structure analyses of [Ag(N-R-ATH)] (BF4) (R = Bn and Ph2CH) revealed monomeric tetra-S-coordinated complex cation structures without the N-coordination, and a benzene ring of the N-R group covered over the amine nitrogen atom. The precise extraction analyses of a Ag(I) ion with ATH derivatives (L = N-R-ATHs and N-H-ATH) associated with the H-1 NMR analyses of the [Ag(L)](+) complexes in polar and non-polar solvents revealed that the introduction of the N-substituent significantly enhanced the extractability of Ag+, due to the "hydrophobic cover" effect by the Ph-C-N framework in the [Ag(N-R-ATH)]+ complexes.
DOI： 10.1039/C6DT01535B
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Development of New Molecular Recognition Modules Constructed via Reversible Spiroborate Formation Reviewed
Hiroshi Danjo
Journal of Synthetic Organic Chemistry 73 ( 7 ) 713 - 722 2015.7
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Multilayered Inclusion Nanocycles of Anionic Spiroborates Reviewed
Hiroshi Danjo, Yuki Kidena, Masatoshi Kawahata, Hiroyasu Sato, Kosuke Katagiri, Toshifumi Miyazawa, Kentaro Yamaguchi
ORGANIC LETTERS 17 ( 17 ) 2466 - 2469 2015.4
Joint Work
Authorship：Lead author, Corresponding author Publisher：AMER CHEMICAL SOC
Multilayered spiroborate nanocycles were prepared from trisor tetrakis(dihydroxynaphthalene) and tetrahydroxyanthraquinone as pillar and crossbar units via the reversible formation of a spiroborate linkage. The four-layered spiroborate nanocycle recognized two cationic aromatic guests simultaneously and exhibited the ability to forth a supramolecular one-dimensional array by combining with methyl viologen dimer as the ditopic guest.
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Nestable Tetrakis(spiroborate) Nanocycles Reviewed
Hiroshi Danjo, Yuhki Hashimoto, Yuki Kidena, Ayumi Nogamine, Kosuke Katagiri, Masatoshi Kawahata, Toshifumi Miyazawa, Kentaro Yamaguchi
ORGANIC LETTERS 17 ( 17 ) 2154 - 2157 2015.4
Joint Work
Authorship：Lead author, Corresponding author Publisher：AMER CHEMICAL SOC
Multicomponent construction of the tetrakis(spiroborate) anionic nanocycles was achieved by reacting bis(dihydroxynaphthalene)s with tetrahydroxyanthraquinone in the presence of boric acid in a self-organized manner. These nanocycles exhibited selective molecular recognition behavior toward cationic guests such as methyl viologen derivatives. Formation of a supramolecular ring@ring and a guest@ring@ring structure was observed by combining the anionic nanocycle and the vinylogous analog of cyclobis(paraquat-p-phenylene).
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Hiroshi Danjo, Toshi Nakagawa, Kosuke Katagiri, Masatoshi Kawahata, Seiki Yoshigai, Toshifumi Miyazawa, Kentaro Yamaguchi
CRYSTAL GROWTH & DESIGN 15 ( 15 ) 384 - 389 2014.11
Joint Work
Authorship：Lead author, Corresponding author Publisher：AMER CHEMICAL SOC
Lanthanide(III)-containing metallosupramolecular arrays were prepared in the crystalline state simply by mixing trifluoromethanesulfonate salts of yttrium(III), lanthanum(III), europium(III), terbium(III), erbium(III), and ytterbium(III) with a rac-tris(spiroborate) twin bowl in N,N-dimethylformamide (DMF). In the crystal, the lanthanide(III) ion coordinated to eight or nine DMF molecules to form spherical tricationic complexes, and the spiroborate twin bowl iteratively glued the complexes to each other to form one-dimensional arrays that were unidirectionally packed in the crystal. In each case, the array structure was stabilized by many aromatic C-H center dot center dot center dot pi interactions and C-H center dot center dot center dot O hydrogen bonds between the twin bowls and the lanthanide(III) complexes. Among the lanthanide(III) ions, yttrium(III), terbium(III), erbium(III), and ytterbium(III) gave almost the same crystal lattice and packing, whereas a different array structure and crystal packing was observed when lanthanum(III) and europium(III) were used, probably due to the difference of the ionic radii of the lanthanide(III) ions.
DOI： 10.1021/cg5014686
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Toshifumi Miyazawa, Masato Yamamoto, Hiroshi Danjo
MONATSHEFTE FUR CHEMIE 144 ( 9 ) 1351 - 1354 2013.9
Joint Work
Publisher：SPRINGER WIEN
Highly selective acylation of the phenolic hydroxy group can be achieved with (hydroxyalkyl)phenols carrying both alcoholic and phenolic hydroxyls by the use of vinyl carboxylates as acyl donors in the presence of rubidium fluoride.
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Preparation of Tris(spiroorthocarbonate) Cyclophanes as Back to Back Ditopic Hosts Reviewed
Hiroshi Danjo, Kazuhisa Iwaso, Masatoshi Kawahata, Kazuaki Ohara, Toshifumi Miyazawa, Kentaro Yamaguchi
ORGANIC LETTERS 15 ( 9 ) 2164 - 2167 2013.4
Joint Work
Authorship：Lead author, Corresponding author Publisher：AMER CHEMICAL SOC
Twin-bowl-shaped tris(spiroorthocarbonate) cyclophanes were designed and prepared as ditopic hosts for electrically neutral or electron-rich guests. Preparation of the desired cyclophanes was achieved by cyclotrimerization of 2,2',3,3'-tetrahydroxy-1,1'-binaphthyl (THB) via the transesterification of tetraphenyl orthocarbonate or dichlorodiphenoxymethane. In those reactions, bis(spiroorthocarbonate) cyclophane containing two THB units was also formed as the kinetically favored product. The spiroorthocarbonate twin bowl exhibited ditopic molecular recognition toward fullerene C-60 in the crystalline state.
DOI： 10.1021/ol4006882
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Chemoselective acylation of (hydroxyalkyl)phenols catalyzed by Candida antarctica lipase B Reviewed
Toshifumi Miyazawa, Masato Yamamoto, Hiroshi Danjo
BIOTECHNOLOGY LETTERS 35 ( 4 ) 625 - 630 2013.4
Joint Work
Publisher：SPRINGER
Acylation of (hydroxyalkyl)phenols with vinyl esters by lipase B from Candida antarctica proceeded smoothly in a highly chemoselective manner, affording their alkyl esters exclusively or at least predominantly. The enzyme therefore discriminates between an alcoholic hydroxyl from a phenolic hydroxyl in addition to having versatile catalytic abilities for organic synthesis.
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A Crystal Structure of Methanesulfonate Salt of 4-(N-Methyl)pyridinium Boronic Acid Reviewed
Satoshi Iwatsuki, Yuki Kanamitsu, Hidetaka Ohara, Masatoshi Kawahata, Hiroshi Danjo, Koji Ishihara
X-ray Struct. Anal. Online 28 63 - 64 2012.8
Joint Work
The structure of a methanesulfonate salt of 4-(N-methyl)pyridinium boronic acid, [4-(N-Me)PyB(OH)2]CH3SO3·H2O, was determined by X-ray crystallography, and was characterized as: P1, a = 5.6937(16), b = 7.805(2), c = 13.522(3)Å, α = 99.46(3), β = 91.45(3), γ = 108.014(17)°, Z = 2, V = 561.8(2)Å3. In the crystals, the cation and the anion are linked by BOH…O(anion), BOH…O(water), and (water)OH…O(anion) hydrogen bonds to stabilize the 1:1:1-cation:anion:water salt unit.
Other Link： https://www.jstage.jst.go.jp/article/xraystruct/28/0/28_63/_article
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Polymorphism of Aromatic Sulfonamides with Fluorine Groups Reviewed
Sho Terada, Kosuke Katagiri, Hyuma Masu, Hiroshi Danjo, Yoshihisa Se, Masatoshi Kawahata, Masahide Tominaga, Kentaro Yamaguchi, Isao Azumaya
CRYSTAL GROWTH & DESIGN 12 ( 6 ) 2908 - 2916 2012.4
Joint Work
Publisher：AMER CHEMICAL SOC
N-(2-Phenoxyphenyl)benzenesulfonamide (1) and fluorine-substituted N-(2-phenoxyphenyl)benzene sulfonamides (2-5) were designed to examine the effect of a fluorine group in the polymorphism of aromatic sulfonamides. Single-crystal X-ray analysis revealed that those with a fluorine (2-5) afforded polymorphs or pseudopolymorphs while the sulfonamide without fluorine (1) did not. From the differential scanning calorimetry measurements, stable (2a-5a) and metastable (2b-5b) crystalline forms were identified. The sulfonamide 1 formed a dimer through hydrogen bonds (H-bonds), which were aligned into two-dimensional (2D) layers via pi/pi and CH/pi interactions. In 2b, 3b, and 4a, the sulfonamide constructed a dimer through H-bonds, which formed 2D layers via CH/F interactions. The sulfonamides 4 formed a one-dimensional (1D) straight chain via H-bonds, which were arranged into 2D layers via CH/F, CH/O, and CH/pi interactions in 4b. The sulfonamide 5 either formed a dimer through H-bonds, which formed 2D layers via CH/O and pi/pi interactions in 5a, or formed a 1D straight chain via CH/O and pi/pi interactions, which were arranged into 2D layers via F/F and CH/F interactions in 5b. In the pseudopolymorph 5c, the sulfonamide 5 formed a 1D zigzag chain via CH/F interactions and was assembled into 2D layers via pi/pi interactions.
DOI： 10.1021/cg300098q
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Tris(spiroborate)-Type Anionic Nanocycles Reviewed
Hiroshi Danjo, Natsuyo Mitani, Yusuke Muraki, Masatoshi Kawahata, Isao Azumaya, Kentaro Yamaguchi, Toshifumi Miyazawa
CHEMISTRY-AN ASIAN JOURNAL 7 ( 7 ) 1529 - 1532 2012.4
Joint Work
Authorship：Lead author, Corresponding author Publisher：WILEY-V C H VERLAG GMBH
New cyclic tris(spiroborate)s were prepared as molecular recognition modules for nanometer-sized cationic guests. These cyclophanes were simply prepared by treating corresponding bis(2,3-dihydroxynaphthalene)s with an equimolar amount of boric acid. The molecular recognition ability of these cyclic spiroborates was estimated in solution and crystal phases by the use of [Ir(tpy2)]3+ as a typical example of a cationic guest.
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Polymorphism of Aromatic Sulfonamides with Fluorine Groups
Terada, S, Katagiri, K, Masu, H, Danjo, H, Kawahata, M, Tominaga, M, Yamaguchi, K, Azumaya, I
RSC Adv. 2 4359 - 4363 2012
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A crystal structure of methanesulfonate salt of 3-(N-methyl)pyridinium boronic acid Reviewed
Satoshi Iwatsuki, Yuki Kanamitsu, Hiroshi Danjo, Koji Ishihara
X-ray Structure Analysis Online 27 ( 10 ) 61 - 62 2011.10
Joint Work
Publisher：Japan Society for Analytical Chemistry
The structure of methanesulfonate salt of 3-(N-methyl)pyridinium boronic acid, [3-(N-Me)PyB(OH)2]CH3SO3, was determined by X-ray crystallography. The boronic acid salt existed in crystals as a monomeric form with a pair of strong O-H...O-S hydrogen bonds, and was characterized as: P21/c, a = 8.9460(18), b = 8.8380(18), c = 13.850(3)Å, β = 105.28(3)°, Z = 4, V = 1056.3(4)Å3. © 2011 The Japan Society for Analytical Chemistry.
Other Link： https://www.jstage.jst.go.jp/article/xraystruct/27/0/27_0_61/_article
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Assembly Modulation by Adjusting Countercharges of Heterobimetallic Supramolecular Polymers Composed of Tris(spiroborate) Twin Bowls Reviewed
Hiroshi Danjo, Kadzuya Hirata, Masanori Noda, Susumu Uchiyama, Kiichi Fukui, Masatoshi Kawahata, Isao Azumaya, Kentaro Yamaguchi, Toshifumi Miyazawa
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 132 ( 44 ) 15556 - 15558 2010.10
Joint Work
Authorship：Lead author, Corresponding author Publisher：AMER CHEMICAL SOC
Heterobimetallic supramolecular polymers were prepared by treatment of the supramolecular polymers composed of tris(spiroborate) type molecular connecting modules with a potassium cation. On the other hand, the addition of a barium cation led to dissociation of the supramolecular polymer chain. Modulation of polymer formation was realized by the use of small metal cations as a control factor.
DOI： 10.1021/ja1084964
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Ionic probe attachment ionization mass spectrometry Reviewed
Fumihiro Ito, Tomoko Nakamura, Satoko Yorita, Hiroshi Danjo, Kentaro Yamaguchi
TETRAHEDRON LETTERS 50 ( 46 ) 6252 - 6255 2009.9
Joint Work
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
A new ionization method that uses metal-complex-based ionization probes containing the 2,6-bis(oxazolinyl)pyridine (pybox) ligand is presented. This method was proven to effectively ionize large complex molecules, including biomolecules. The preparation of the charged probes and their application to the ionization of biomolecules using cold-spray ionization mass spectrometry are shown. (C) 2009 Elsevier Ltd. All rights reserved.
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SYNTHESIS OF OPTICALLY ACTIVE P-CHIROGENIC FERROCENE-FUSED BENZOPHOSPHOLE BY DIASTEREOSELECTIVE INTRAMOLECULAR CYCLIZATION OF PHOSPHANYLFERROCENE DERIVATIVES Reviewed
Shuji Yasuike, Jun-ichi Hagiwara, Hiroshi Danjo, Masatoshi Kawahata, Naoki Kakusawa, Kentaro Yamaguchi, Jyoji Kurita
HETEROCYCLES 78 ( 12 ) 3001 - 3010 2009.7
Joint Work
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
A novel optically active P-chirogenic ferrocene-fused benzophosphole, (S(Fc),R(P))-4-phenylbenzo[b]ferroceno[d]phosphole, was synthesized by diastereoselective intramolecular cyclization of (S(Fc))-1-(diphenylphosphanyl)2-(2-lithiophenyl)ferrocene intermediates in two routes. The geometry of the new P-chirogenic ferrocenophosphole including absolute configuration of the phosphorous was disclosed by single crystal X-ray analysis of the palladium complex derived from the reaction of the phosphole with di-mu-dichloro-bis{2-[(dimethylamino)methyl]phenyl-C(1),N}dipalladium (II).
DOI： 10.3987/COM-09-11812
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Back to Back Twin Bowls of D-3-Symmetric Tris(spiroborate)s for Supramolecular Chain Structures Reviewed
Hiroshi Danjo, Kadzuya Hirata, Seiki Yoshigai, Isao Azumaya, Kentaro Yamaguchi
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 131 ( 131 ) 1638 - 1639 2009.2
Joint Work
Authorship：Lead author, Corresponding author Publisher：AMER CHEMICAL SOC
A new class of D-3-symmetric tris(spiroborate) cyclophanes has been designed and prepared for the construction of supramolecular chain structures by iterative host-guest interaction with ditopic guest molecules. The treatment of these compounds with [Ir(tpy)(2)](PF6)(3) complex in solution led to the formation of the chain structure, which was confirmed by H-1 NMR and CSI-MS studies. The chain structure exhibited rapid temperature-responsive gelation behavior in their HMPA solution.
DOI： 10.1021/ja8071435
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Construction of optically active multimetallic systems of rhodium(I), palladium(II), and ruthenium(II) with a P-chiral tetraphosphine ligand Reviewed
Keiji Yashio, Masatoshi Kawahata, Hiroshi Danjo, Kentaro Yamaguchi, Masaharu Nakamura, Tsuneo Imamoto
JOURNAL OF ORGANOMETALLIC CHEMISTRY 694 ( 694 ) 97 - 102 2008.10
Joint Work
Publisher：ELSEVIER SCIENCE SA
The treatment of optically P-chiral tetraphosphine, (3S, 6R, 9R, 12S)-6,9-di-tert-butyl-2,2,3,12,13,13-hexamethyl3,6,9,12-tetraphosphatetradecane (1), with rhodium(I), palladium(II), and ruthenium( II) complex precursors led to the selective formation of mono-, di-, or trinuclear homo- or heterometallic complexes, [Rh(1)]SbF6 (4), [{Rh(nbd)}(2)(1)](SbF6)(2) (3), [{Pd(eta(3)-allyl)} 2(1)](SbF6)(2) (5), [{RuCl(eta(5)-C-5(CH3)(5))}(2)(1)] (6), and [{RuCl2(eta(6)-benzene)}(2)(PdCl2)(1)] (8). These complexes were characterized by NMR and X-ray crystallographic analysis. (C) 2008 Elsevier B. V. All rights reserved.
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Formation of 1,4-diphosphinobenzenes via tele-substitution on fluorobenzenechromium complexes Reviewed
Yoshikazu Yamamoto, Hiroshi Danjo, Kentaro Yamaguchi, Tsuneo Imamoto
JOURNAL OF ORGANOMETALLIC CHEMISTRY 693 ( 693 ) 3546 - 3552 2008.8
Joint Work
Publisher：ELSEVIER SCIENCE SA
The meta-tele-substitution of 2-(boranatophosphino) fluorobenzenechromium complexes took place with various lithiated secondary phosphine-boranes as nucleophiles to give para-substituted bis(boranatophosphino) benzenechromiums. It was revealed that the yield of the tele-substitution product was strongly affected by the strength of a proton acid. Isotope labeling experiments indicated that 1,5-hydrogen migration was involved in this transformation. (C) 2008 Elsevier B.V. All rights reserved.
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Catalytic activities of Pd-tailored single wall carbon nanohorns Reviewed
Tsutomu Itoh, Hiroshi Danjo, Wataru Sasaki, Koki Urita, Elena Bekyarova, Miki Arai, Tsuneo Imamoto, Masako Yudasaka, Sumio Iijima, Hirofumi Kanoh, Katsumi Kaneko
CARBON 46 ( 46 ) 172 - 175 2007.11
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Facile synthesis of highly congested 1,2-diphosphinobenzenes from bis(phosphine)boronium salts Reviewed
Yoshikazu Yamamoto, Toru Koizumi, Kosuke Katagiri, Yui Furuya, Hiroshi Danjo, Tsuneo Imamoto, Kentaro Yamaguchi
ORGANIC LETTERS 8 ( 8 ) 6103 - 6106 2006.11
Joint Work
Publisher：AMER CHEMICAL SOC
Bis(phosphine)boronium salts 3a-c were designed and prepared as key building blocks for the synthesis of highly congested diphosphinobenzenes. The preparation of sterically hindered ortho-phenylene-bridged diphosphines 1a-c was achieved by the reaction of the bis(phosphine)boronium salts 3a-c with difluorobenzenechromium complex 2 and subsequent removal of the BH2 group. The steric nature of diphosphine 1a was revealed in single-crystal X-ray analysis of its Rh complex.
DOI： 10.1021/ol062717i
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Combinatorial approach to heterogeneous asymmetric aquacatalysis with amphiphilic polymer-supported chiral phosphine-palladium complexes Reviewed
Yukinari Kobayashi, Daiki Tanaka, Hiroshi Danjo, Yasuhiro Uozumi
ADVANCED SYNTHESIS & CATALYSIS 348 ( 348 ) 1561 - 1566 2006.6
Joint Work
Publisher：WILEY-V C H VERLAG GMBH
A library of amphiphlic polystyrene-poly(ethylene glycol) (PS-PEG) resin-supported chiral phosphine ligands was prepared by the split method using porous miniature reactors. A polymeric (R)-2-(diphenylphosphino)binaphthyl (MOP) ligand anchored onto the PS-PEG resin by an (S)-alanine tether unit was identified through the library-based screening to be an effective chiral ligand for the asymmetric palladium-catalyzed pi-allylic substitution under heterogeneous aqueous conditions.
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Assembly state of catalytic modules as chiral switches in asymmetric strecker amino acid synthesis Reviewed
Nobuki Kato, Tsuyoshi Mita, Motomu Kanai, Bruno Therrien, Masaki Kawano, Kentaro Yamaguchi, Hiroshi Danjo, Yoshihisa Sei, Akihiro Sato, Sanae Furusho, Masakatsu Shibasaki
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 128 ( 128 ) 6768 - 6769 2006.5
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P-chiral o-phosphinophenol as a P/O hybrid ligand: Preparation and use in Cu-catalyzed asymmetric conjugate addition of diethylzinc to acyclic enones Invited Reviewed
Y Takahashi, Y Yamamoto, K Katagiri, H Danjo, K Yamaguchi, T Imamoto
JOURNAL OF ORGANIC CHEMISTRY 70 ( 70 ) 9009 - 9012 2005.9
Joint Work
Publisher：AMER CHEMICAL SOC
(S)-2-(tert-Butylmethylphosphino)phenol and its methyl ether were synthesized from tert-butyldichlorophosphine via optically active phosphine-boranes as the intermediates. The former compound was used as a P/O hybrid ligand in the Cu-catalyzed asymmetric conjugate addition of diethylzinc to acyclic enones to achieve high enantioselectivity of up to 96%.
DOI： 10.1021/jo051034y
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Nucleophilic aromatic substitution reactions of fluorobenzenechromium complexes with P-chiral secondary phosphine-boranes: synthesis of optically pure P-chiral (dialkyl)arylphosphine-boranes Reviewed
K Katagiri, H Danjo, K Yamaguchi, T Imamoto
TETRAHEDRON 61 ( 61 ) 4701 - 4707 2005.3
Joint Work
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
Optically pure P-chiral (dialkyl)arylphosphine-boranes having high structural diversity were prepared by two- or three-component coupling of fluorobenzenechromium complexes, P-chiral secondary phosphine-boranes, and other nucleophiles. The stereochernical integrity at the P-stereogenic center was completely retained during the SNAr process when the reaction was carried out in THF at low temperature. (c) 2005 Elsevier Ltd. All rights reserved.
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Dihydroboronium derivatives of (S,S)-1,2-bis(t-butylmethylphosphino)ethane as convenient chiral ligand precursors Reviewed
T Miyazaki, M Sugawara, H Danjo, T Imamoto
TETRAHEDRON LETTERS 45 ( 45 ) 9341 - 9344 2004.11
Joint Work
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
Dihydroboroniurn derivatives of (S,S)-1,2-bis(t-butylmethylphosphino)ethane (t-Bu-BisP*) were prepared and used as chiral diphosphine ligand precursors in Rh-catalyzed asymmetric hydrogenation of methyl (Z)-acetamidocinnamate to afford the hydrogenation product in up to 94% enantioselectivity. (C) 2004 Elsevier Ltd. All rights reserved.
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Cooperative dual catalysis: Application to the highly enantioselective conjugate cyanation of unsaturated imides Reviewed
GM Sammis, H Danjo, EN Jacobsen
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 126 ( 126 ) 9928 - 9929 2004.7
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P-stereogenic P/N hybrid ligands: a remarkable switch in enantioselectivity in palladium-catalyzed asymmetric allylation Reviewed
H Danjo, M Higuchi, M Yada, T Imamoto
TETRAHEDRON LETTERS 45 ( 45 ) 603 - 606 2003.10
Joint Work
Authorship：Lead author Publisher：PERGAMON-ELSEVIER SCIENCE LTD
Optically active P-stereogenic phosphine/oxazoline bidentate ligands (1) were prepared and applied to palladium-catalyzed allylic substitution of 1,3-diphenyl-1-acetoxy-2-propene with dimethyl malonate. The absolute configuration of the allylation product was remarkably switched by changing a palladium/ligand ratio between 1/1 and 1/2. (C) 2003 Elsevier Ltd. All rights reserved.
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P-Chirogenic phosphonium salts: preparation and use in Rh-catalyzed asymmetric hydrogenation of enamides
H Danjo, W Sasaki, T Miyazaki, T Imamoto
TETRAHEDRON LETTERS 44 ( 44 ) 3467 - 3469 2003.3
Joint Work
Authorship：Lead author Publisher：PERGAMON-ELSEVIER SCIENCE LTD
P-Chirogenic trialkylphosphonium salts were prepared from the corresponding free phosphines by treatment with a strong acid (HBF4 or HOPf). No racemization of the phosphonium salts occurred in methanol or water even at considerably high temperature. The salts were conveniently used in rhodium-catalyzed asymmetric hydrogenation of enamides. (C) 2003 Elsevier Science Ltd. All rights reserved.
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Formation of indole nucleus via intramolecular cyclization of aminophenylpropenyltriphenylphosphonium salts with one-carbon degradation Reviewed
S Taira, H Danjo, T Imamoto
TETRAHEDRON LETTERS 43 ( 43 ) 8893 - 8896 2002.10
Joint Work
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
Treatment of 3-(2-aminoplienyl)-2-propenyltriphenylphosphonium bromide with acid anhydride and tertiary amine affords 1,3-diacylindoles in yields ranging from 22 to 64%. A plausible mechanism of this new cyclization reaction is described. (C) 2002 Published by Elsevier Science Ltd.
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Preparation of an optically active bis(diethylphosphino)biphenyl ligand designed for highly reactive catalytic processes Reviewed
T Shibata, H Tsuruta, H Danjo, T Imamoto
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL 196 ( 196 ) 117 - 124 2002.7
Joint Work
Publisher：ELSEVIER SCIENCE BV
New optically active diphosphine ligands, (S)-2,2'-bis(diphenylphosphino)-3,3',4,4',5,5',6,6'-octamethylbiphenyl (2a) and (S)-2,2'-bis(diethylphosphino)-3,3',4,4',5,5',6,6'-octamethylbiphenyl (2c) were prepared via optical resolution of the corresponding phosphine oxides. The Rh complex of 2c proved efficient in the catalytic asymmetric hydrogenation of a dehydroamino acid derivative even at -50degreesC and gave 88% e.e. of hydrogenation product quantitatively. (C) 2002 Elsevier Science B.V. All rights reserved.
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A facile synthesis of 2-substituted indoles from (2-aminobenzyl)triphenylphosphonium salts Reviewed
S Taira, H Danjo, T Imamoto
TETRAHEDRON LETTERS 43 ( 43 ) 2885 - 2888 2002.3
Joint Work
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
A variety of 2-substituted 1-acylindoles were obtained in yields ranging from 40 to 94% by intramolecular Wittig reaction employing (2-aminobenzyl)triphenylphosphonium derivatives and acid anhydride in the presence of triethylamine. The reaction of (2-aminobenzyl)phosphonium derivatives with various acyl chlorides in 2.6-lutidine also proceeded to give the corresponding indoles in 28-67% yields. (C) 2002 Elsevier Science Ltd. All rights reserved.
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P-chirogenic phosphine/sulfide hybrid ligands Reviewed
H Sugama, H Saito, H Danjo, T Imamoto
SYNTHESIS-STUTTGART ( 15 ) 2348 - 2353 2001.7
Joint Work
Publisher：GEORG THIEME VERLAG KG
P-Chirogenic phosphine/sulfide hybrid ligands I were prepared by the use of optically active phosphine-boranes as the intermediates. The palladium complexes of the ligands exhibited high catalytic activity and enantioselectivity in allylic alkylation of 1-acetoxy-1,3-diphenylprop-2-ene with malonate esters.
DOI： 10.1055/s-2001-18433
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Allylic substitution in water catalyzed by amphiphilic resin-supported palladium-phosphine complexes Reviewed
H Danjo, D Tanaka, T Hayashi, Y Uozumi
TETRAHEDRON 55 ( 55 ) 14341 - 14352 1999.10
Joint Work
Authorship：Lead author Publisher：PERGAMON-ELSEVIER SCIENCE LTD
New amphiphilic resin-supported triarylphosphines PEP (1) were designed and prepared on polyethylene glycol-polystyrene graft copolymer (PEG-PS). Palladium complexes of 1, Pd(PEP)(2) (4) and Pd(PEP) (5), catalyzed allylic alkylation of 3-acetoxy-1,3-diphenyl-1-propene (6) and cinnamyl acetate (7) with various nucleophiles including 1,3-dicarbonyl compounds, amino acids, sodium azide, and sodium sulfinate, to give quantitative yields of corresponding allylic substituted products in water. (C) 1999 Elsevier Science Ltd. All rights reserved.
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New Amphiphilic Palladium-Phosphine Complexes Bound to Solid Supports: Preparation and Use for Palladium-Catalyzed Reactions in Aqueous Media
Hiroshi Danjo
1999.3
Single Work
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Cross-coupling of aryl halides and allyl acetates with arylboron reagents in water using an amphiphilic resin-supported palladium catalyst Reviewed
Y Uozumi, H Danjo, T Hayashi
JOURNAL OF ORGANIC CHEMISTRY 64 ( 64 ) 3384 - 3388 1998.12
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Palladium-catalyzed asymmetric allylic substitution in aqueous media using amphiphilic resin-supported MOP ligands Reviewed
Y Uozumi, H Danjo, T Hayashi
TETRAHEDRON LETTERS 39 ( 39 ) 8303 - 8306 1998.8
Joint Work
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
A series of amphiphilic resin-supported MOP ligands PEP-MOP were prepared on a polyethylene glycol-polystyrene graft copolymer. Palladium complexes of EP-MOP were found to be effective as catalysts for the asymmetric substitution of 1,3-diphenyl-2-propenyl acetate with 3-methyl-2,4-pentanedione in aqueous K2CO3 to give 1,3-diphenyl-4-acetyl-4-methyl-1-hexen-5-one of up to 81% ee. (C) 1998 Elsevier Science Ltd. All rights reserved.
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New amphiphilic palladium-phosphine complexes bound to solid supports: Preparation and use for catalytic allylic substitution in aqueous media Reviewed
Y Uozumi, H Danjo, T Hayashi
TETRAHEDRON LETTERS 38 ( 38 ) 3557 - 3560 1997.4
Joint Work
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
New amphiphilic palladium-phosphine complexes were designed and prepared on polyethylene glycol-polystyrene graft copolymer (PEG-PS) resin. The solid-supported palladium complexes showed high catalytic activity in allylic substitution reactions of allyl acetates with various nucleophiles in aqueous media. (C) 1997 Elsevier Science Ltd.
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DNA cleavage of novel propargylic sulfones. Enhancement of potency via intercalating interaction Reviewed
WM Dai, KC Fong, H Danjo, S Nishimoto, M Solow, WL Mak, ML Yeung
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS 6 ( 6 ) 1093 - 1098 1996.4
Joint Work
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
A number of novel hydroxy propargylic sulfones 7-15 were synthesized as DNA cleaving agents. Enhancement of DNA cleavage potency was observed with those compounds which could interact with DNA through intercalation of the extended aromatic rings. (C) 1996 Elsevier Science Ltd
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Synthesis of cis-enediynes from 1,5-diynes by rearrangement of an allylic double bond Reviewed
WM Dai, KC Fong, H Danjo, S Nishimoto
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH 35 ( 35 ) 779 - 781 1995.11