研究者詳細 - 押木　俊之

MISC - 押木　俊之

分割表示 99 件中 81 - 99 件目／全件表示 >>

Tp*Sn(Cl)Bu₂ as a Convenient Reagent for the Preparation of Hydrotris(3,5-Dimethylpyrazolyl)borate Complexes of Niobium, Tantalum, and Zirconium"jointly worked"

Mashima K, Oshiki T, Tani K

Organometallics 16 ( 13 ) 2760 - 2762 1997年

Oxidative Reaction of 1,5-Dithioniabicyclo[3.3.0]octane Bis(trifluoromethanesulfonate)with Diene Complexes of Zirconium and Tantalum : Rational Preparation of Cp₂Zr(COf)₂(thf)and Cp(η⁴-1,3 butadiene)Ta(OTf)₂(共著)

Mashima K, Oshiki T, Matsuo Y, Tani K

Chemistry Letters ( 8 ) 793 - 794 1997年

Oxidative Reaction of 1,5-Dithioniabicyclo[3.3.0]octane Bis(trifluoromethanesulfonate) with Diene Complexes of Zirconium and Tantalum : Rational Preparation of Cp₂Zr(COf)₂(thf)and Cp(η⁴-1,3 butadiene)Ta(OTf)₂・・・

Mashima K, Oshiki T, Matsuo Y, Tani K

Chemistry Letters ( 8 ) 793 - 794 1997年

Living Polymerization of Ethylene Catalyzed by Diene Complexes of Niobium and Tantalum K(η⁵-C₅H₅)(η⁴-diene)X₂ and M(η⁵-C₅Me₅)(η⁴-diene)₂(M=Nb ・・・

MASHIMA K, FUJIKAWA S, TANAKA Y, URATA H, OSHIKI T, TANAKA E, NAKAMURA A

Organometallics 14 ( 6 ) 2633 - 2640 1995年6月

記述言語：英語掲載種別：書評論文，書評，文献紹介等

Living Polymerization of Ethylene Catalyzed by Diene Complexes of Niobium and Tantalum K(η5-C5H5)(η4-diene)X2 and M(η5-C5Me5)(η4-diene)2(M=Nb and Ta), in the Presence of Methylaluminoxane(共著)

DOI： 10.1021/om00006a008

Web of Science

researchmap

LIVING POLYMERIZATION OF ETHYLENE CATALYZED BY DIENE COMPLEXES OF NIOBIUM AND TANTALUM, M(ETA(5)-C(5)ME(5))(ETA(4)-DIENE)X(2) AND M(ETA(5)-C(5)ME(5))(ETA(4)-DIENE)(2)(M= NB AND TA), IN THE PRESENCE OF METHYLALUMINOXANE

K MASHIMA, S FUJIKAWA, Y TANAKA, H URATA, T OSHIKI, E TANAKA, A NAKAMURA

ORGANOMETALLICS 14 ( 6 ) 2633 - 2640 1995年6月

記述言語：英語掲載種別：書評論文，書評，文献紹介等出版者・発行元：AMER CHEMICAL SOC

Catalyst systems of MX(2)(eta(5)-C(5)R(5))(eta(4)-diene) (M = Nb and Ta; R = H and CH3; X = Cl and CH3) in a combination of methylaluminoxane (MAO) are the precursors of the living polymerization of ethylene. Mono-diene complexes MCl(2)(eta(5)-C(5)R(5))(eta(4)-diene) [M = Nb, R = CH3 (1); M = Ta, R = CHS (2); M = Ta, R = H (3); M = Nb, R = H (4); diene = buta-1,3-diene (a), isoprene (b), 2,3-dimethylbuta-1,3-diene (c)] were prepared by the reaction of MCl(4)(eta(5)-C(5)R(5)) with 2 equiv of the methylated allyl Grignard reagents in THF. Reaction of 2 and 3 with MeMgI afforded dimethyl complexes, Ta(eta(5)-C(5)R(5))(eta(4)-1,3-butadiene)Me(2) [R = CH3 (5); R = H (6)], respectively. The polymerization of ethylene catalyzed by 1/MAO, 2/MAO, and 5/MAO at low temperature (-20 degrees C) gave polyethylene with very narrow polydispersities (M(w)/M(n) as low as 1.05). The niobium complexes are superior to the tantalum complexes in terms of the catalyst activity and the polydispersity. When the ligand was Cp instead of Cp*, the catalyst activity of 3 for the polymerization of ethylene at -20 degrees C increased but the polydispersity of the obtained polyethylene broadened (M(w)/M(n) = 1.40). Protolytic reaction of 5b with 1 equiv of TfOH produces TaCp*(eta 4-isoprene)(CH3)(OSO2CF3) (7), whose structure is determined by single-crystal X-ray diffractometry. Compound 7 crystallizes in the orthorhombic space group P2(1)2(1)2(1) (No. 19) with a = 13.388(6) Angstrom, b = 16.196(4) Angstrom, c = 9.214(4) Angstrom, Z = 4, V = 1998(1) Angstrom(3), D-calcd = 1.823 g/mL, and R = 0.041 based on 2191 reflections. The molecular structure shows that 7 is not a cationic complex. The tantalum atom is in a chiral center surrounded by four different ligands: eta(1)-triflate, eta(5)-Cp*, eta(4)-isoprene, and methyl. A cationic species derived from 5b and B(C6F5)(3) was detected by H-1 NMR spectroscopy and found to be active in ethylene polymerization. A system of one of the bis-diene complexes of the type M(eta 5-C(5)R(5))(eta(4)-2,3-dimethyl-1,3-butadiene)(2) [M = Nb, R = H (8); M = Nb, R = CH3 (9); M = Ta, R = CH3 (10)] in the presence of a large excess of MAO was also found to be an active catalyst for the polymerization of ethylene.

DOI： 10.1021/om00006a008

Web of Science

researchmap

SYNTHESIS AND REACTIONS OF OPTICALLY-ACTIVE PHOSPHINE-BORANES

T IMAMOTO, T OSHIKI, T ONOZAWA, M MATSUO, T HIKOSAKA, M YANAGAWA

HETEROATOM CHEMISTRY 3 ( 5-6 ) 563 - 575 1992年10月

記述言語：英語出版者・発行元：JOHN WILEY & SONS INC

Synthesis and reactions of optically active phosphine-boranes have been investigated. Optically active secondary phosphine-boranes, (S(p))-and (R(p))-menthyloxyphenylphosphine-boranes, and (S)-methylphenylphosphine-borane underwent palladium(0)-catalyzed electrophilic arylation with o-, m-, or p-iodoanisole. The stereochemistry of this arylation was largely dependent on the solvent and the base used. The reaction in acetonitrile proceeded with almost complete retention of configuration at the chiral phosphorus, whereas inversion of configuration was observed in ethereal solvents or toluene. The phosphorus-oxygen bond of (R(p))-menthyloxy (methyl)phenylphosphine-borane and (S(p))-menthy-loxy(o-methoxyphenyl)phenylphosphine-borane was reductively cleaved at -78-degrees-C by lithium naphthalenide or Li/NH3 with virtually net retention of configuration at phosphorus, providing secondary or tertiary phosphine-boranes in excellent yields. New synthetic routes to optically pure C2-symmetric bisphosphine-boranes possessing chirality at phosphorus have been developed on the basis of these stereochemical studies.

Web of Science

researchmap

Synthesis and Reactions of Optically Active Phosphine-Boranes(共著)

Toshiyuki Oshiki, Tsuneo Imamoto

Heteroatom Chemistry 3 ( 5-6 ) 563 - 575 1992年10月

Unprecedented Stereochemistry of the Electrophilic Arylation at Chiral Phosphorus(共著)

OSHIKI T, IMAMOTO T

Journal of the American Chemical Society 114 ( 10 ) 3975 - 3977 1992年5月

Unprecedented Stereochemistry of the Electrophilic Arylation at Chiral Phosphorus"jointly worked"

OSHIKI T, IMAMOTO T

Journal of the American Chemical Society 114 ( 10 ) 3975 - 3977 1992年

STEREOSPECIFIC REDUCTION OF MENTHYLOXYPHOSPHINE-BORANES WITH ONE-ELECTRON REDUCING AGENTS

T OSHIKI, T HIKOSAKA, T IMAMOTO

TETRAHEDRON LETTERS 32 ( 28 ) 3371 - 3374 1991年7月

Stereospecific Reduction of Menthyloxyphosphine-Boranes with One Electron Reducing Agents(共著)

Toshiyuki Oshiki, Tsuneo Imamoto

Tetrahedron Letters 32 ( 28 ) 3371 - 3374 1991年7月

THE REACTIONS OF OPTICALLY PURE METHYLOXYMETHYLPHENYLPHOSPHINE-BORANE WITH ORGANOLITHIUM REAGENTS

T OSHIKI, T IMAMOTO

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 63 ( 12 ) 3719 - 3721 1990年12月

記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）出版者・発行元：CHEMICAL SOC JAPAN

The reactions of (R(p))-methyloxymethyl-phenylphosphine-borane with several organolithium reagents are described. Less sterically hindered reagents such as m-anisyllithium and p-anisyllithium react with the phosphine-borane to afford the corresponding substitution products with high stereochemical integrity with inversion of configuration. On the other hand, omicron-substituted phenyllithiums lead to products possessing very low optical purities.

DOI： 10.1246/bcsj.63.3719

Web of Science

researchmap

The Reactions of Optically Pure Menthyloxymethylphenylphosphine-Borane with Organolithium Reagents(共著)

OSHIKI T, IMAMOTO T

Bulletin of the Chemical Society of Japan 63 ( 12 ) 3719 - 3721 1990年12月

Synthesis and Reactions of Phosphine-Methylsulfonyloxyborane Complexes(共著)

OSHIKI T, IMAMOTO T

Bulletin of the Chemical Society of Japan 63 ( 10 ) 2846 - 2849 1990年10月

Synthesis and Reactions of Phosphine-Boranes. Synthesis of New Bidentate Ligands with Homochiral Phosphine Centers via Optically Pure Phosphine Boranes(共著)

IMAMOTO T, OSHIKI T, ONOZAWA T, KUSUMOTO T, SATO K

Journal of the American Chemical Society 112 ( 13 ) 5244 - 5252 1990年6月

SYNTHESIS AND REACTIONS OF PHOSPHINE BORANES - SYNTHESIS OF NEW BIDENTATE LIGANDS WITH HOMOCHIRAL PHOSPHINE CENTERS VIA OPTICALLY PURE PHOSPHINE BORANES

T IMAMOTO, T OSHIKI, T ONOZAWA, T KUSUMOTO, K SATO

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 112 ( 13 ) 5244 - 5252 1990年6月

Synthesis and reactions of phosphine-methylsulfonyloxyborane complexes

Toshiyuki Oshiki, Tsuneo Imamoto

Bulletin of the Chemical Society of Japan 63 ( 10 ) 2846 - 2849 1990年

記述言語：英語

Functionalizations of the boranato group of phosphine-boranes have been investigated. Trimethylphosphine-borane readily reacted with methanesulfonic acid in dichloromethane with evolution of hydrogen. The resulting trimethylphosphine-methylsulfonyloxyborane was subjected to nucleophilic substitution reaction on the boron atom with arenethiols or secondary phosphine-boranes in the presence of NaH. The reactivities of the substitution products obtained were also investigated. A new phosphine-borane having a P-B-P-B-P-BP-B bond linkage was synthesized. © 1990 The Chemical Society of Japan.

DOI： 10.1246/bcsj.63.2846

Scopus

researchmap

SYNTHESIS OF ORGANIC PHOSPHORUS-COMPOUNDS CONTAINING A LINEAR P-B BOND CHAIN

T IMAMOTO, T OSHIKI

TETRAHEDRON LETTERS 30 ( 3 ) 383 - 384 1989年

Synthesis of Organic Phosphorus Compounds Containing a Linear P-B Bond Chain(共著)

Toshiyuki Oshiki, Tsuneo Imamoto

Tetrahedron Letters 30 ( 3 ) 383 - 384 1989年

　前のページ - 次のページ　

<押木 俊之>

MISC - 押木 俊之

<押木　俊之>

MISC - 押木　俊之