A5010155058- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Organic Chemistry Cycloaddition Reactions
- Organometallic Complex Synthesis and Catalysis
- Chemical Reaction Mechanisms
- Sulfur-Based Synthesis Techniques
- Synthesis and Reactivity of Sulfur-Containing Compounds
- Synthesis and Catalytic Reactions
- Organoselenium and organotellurium chemistry
- Crystallography and molecular interactions
- Coordination Chemistry and Organometallics
- Chemical Synthesis and Reactions
- Synthesis and characterization of novel inorganic/organometallic compounds
- Porphyrin and Phthalocyanine Chemistry
- Carbon dioxide utilization in catalysis
- Oxidative Organic Chemistry Reactions
- Synthesis of heterocyclic compounds
- Photochromic and Fluorescence Chemistry
- Free Radicals and Antioxidants
- Organoboron and organosilicon chemistry
- Radical Photochemical Reactions
- Synthetic Organic Chemistry Methods
- Fluorine in Organic Chemistry
- Polyoxometalates: Synthesis and Applications
- Synthesis and Properties of Aromatic Compounds
Saitama University
2015-2024
Graduate School USA
2015-2021
RIKEN Advanced Science Institute
2009
Hokuriku University
2009
The University of Tokyo
1984-1996
Bunkyo University
1996
Urawa University
1993-1994
University of Bologna
1988-1991
Several recent efforts concerning post-metallocene Group 4 metal complexes incorporating mixed donor [OSSO]-type tetradentate bis(phenolato) ligands are reviewed. These can be mainly classified as 5–5–5, 5–6–5 and 6–5–6 arrays of chelate rings toward central metals. As the main topics described design unique coordination chemistry catalytic activities resultant titanium, zirconium, hafnium single-site catalysts for polymerizations copolymerizations olefins.
Six-coordinated dibenzyl Zr complex bearing an [OSSO]-type tetradentate ligand was synthesized, and the structure fully characterized by NMR spectroscopy X-ray crystallography. The zirconium has C2 symmetry in solution. Owing to effect of cyclooctane ring structure, combination B(C6F5)3 or (Ph3C)[B(C6F5)4] as activator exhibited high activity toward polymerization 1-hexene yield highly isotactic poly(1-hexene).
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPreparation of a Selenenic Acid and Isolation SelenoseleninatesAkihiko Ishii, Shogo Matsubayashi, Takeshi Takahashi, Juzo NakayamaView Author Information Department Chemistry, Faculty Science, Saitama University, Urawa, 338-8570, Japan Cite this: J. Org. Chem. 1999, 64, 4, 1084–1085Publication Date (Web):January 23, 1999Publication History Received9 October 1998Published online23 January 1999Published inissue 1 February...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and reactions of 1,3,4,6-tetra-2-thienylthieno[3,4-c]thiopheneAkihiko Ishii, Juzo Nakayama, Junichi Kazami, Yutaka Ida, Takao Nakamura, Masamatsu HoshinoCite this: J. Org. Chem. 1991, 56, 1, 78–82Publication Date (Print):January 1991Publication History Published online1 May 2002Published inissue 1 January 1991https://pubs.acs.org/doi/10.1021/jo00001a018https://doi.org/10.1021/jo00001a018research-articleACS PublicationsRequest reuse...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFirst isolation of a stable aliphatic thioaldehyde, tris(trimethylsilyl)ethanethialRenji Okazaki, Akihiko Ishii, and Naoki InamotoCite this: J. Am. Chem. Soc. 1987, 109, 1, 279–280Publication Date (Print):January 1987Publication History Published online1 May 2002Published inissue 1 January 1987https://pubs.acs.org/doi/10.1021/ja00235a046https://doi.org/10.1021/ja00235a046research-articleACS PublicationsRequest reuse permissionsArticle...
Treatment of trans-cyclooctanediyl-bridged [OSSO]-type ligand 1 with Hf(CH2Ph)4 in toluene afforded the corresponding hafnium(IV) dibenzyl complex 5 as pale yellow crystals. X-ray crystallographic analysis revealed that six-coordinated hafnium center incorporated adopted cis-α configuration, and two benzyl ligands were coordinated to by η1-fashion. In polymerization 1-hexene, combination B(C6F5)3, (Ph3C)[B(C6F5)4], or dMAO (dried methylaluminoxane) an activator provided poly(1-hexene)s...
A novel three-coordinated tin(II) chloride [Ph2P(NtBu)2]SnCl (1) supported by an N,N'-di-tert-butyliminophosphonamide having two phenyl groups on the phosphorus atom was synthesized reaction of starting lithium iminophosphonamide [Ph2P(NtBu)2]Li with SnCl2·(dioxane) in toluene. The molecular structure 1 established X-ray diffraction analysis. Tin(II) can act as efficient precatalyst for hydroboration a wide variety aldehydes, ketones, and imines at -10 °C. DFT calculations propose that...
Dithiiranes were hitherto considered unstable and only discussed as elusive intermediates. The dithiirane 1, in contrast, can be readily isolated, purified, characterized by spectroscopy X-ray diffraction well a series of chemical reactions.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis, Isolation, and Full Characterization of the Parent Thiophene 1,1-DioxideJuzo Nakayama, Hidehiro Nagasawa, Yoshiaki Sugihara, Akihiko IshiiView Author Information Department Chemistry, Faculty Science Saitama University, Urawa, 338, Japan Cite this: J. Am. Chem. Soc. 1997, 119, 38, 9077–9078Publication Date (Web):September 24, 1997Publication History Received12 June 1997Published online24 September inissue 1...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis of a Stable Sulfenic Acid by Oxidation Sterically Hindered Thiol (Thiophenetriptycene-8-thiol)1 and Its CharacterizationAkihiko Ishii, Ken Komiya, Juzo NakayamaView Author Information Department Chemistry, Faculty Science Saitama University, Urawa, 338, Japan Cite this: J. Am. Chem. Soc. 1996, 118, 50, 12836–12837Publication Date (Web):December 18, 1996Publication History Received26 August 1996Published online18 December inissue 1...
The title compound, an extremely stable thiobenzaldehyde, was prepared by the reaction of 2,4,6-tri-t-butylphenyl-lithium with O-ethyl thioformate or 2,4,6-tri-t-butylbenzaldehyde hydrazone disulphur dichloride.
Abstract The reaction of [PtH(SeTrip)(PPh 3 ) 2 ] (Trip = 9‐triptycyl) ( with dimethyl acetylenedicarboxylate (DMAD) or methyl propiolate gave hydroselenation syn adducts. [PtH(SeTrip)(dppe)] [dppe 1,2‐bis(diphenylphosphanyl)ethane], which has a stronger phosphane σ‐donor ligand than , DMAD both and anti in the presence PPh yielded no These observations indicate that, hydroselenation, dissociation from is key step. selenaplatinacycle 6 thermal product reacted to give carboselenation product,...
Abstract The N ‐heterocyclic silylene (NHSi) [Ph 2 P( t BuN) ]SiCl ( 1 ), supported by an iminophosphonamide ligand, was obtained from the dehydrochlorination of ]SiHCl ) with LiN(SiMe 3 . NHSi contains extremely high‐energy HOMO level and consequently displays unique coordination behavior toward Rh I complexes. When treated 1/4 equivalent [RhCl(cod)] (cod=1,5‐cyclooctadiene), 14‐electron Y‐shaped bis(chlorosilylene) complex 5 as dark purple crystals. reaction 1/6 yielded cationic...
2-(1,3-Dimethylimidazolidinio)diselenocarboxylate (16) was obtained in 48% yield as thermally stable, dark green crystals by reaction of 2-methylene-1,3-dimethylimidazolidine (7) with Se2Cl2 the presence Et3N. The 16 elemental sulfur gave 2-(1,3-dimethylimidazolidinio)dithiocarboxylate (20) 95% exhaustive selenium−sulfur exchange, whereas use a limited amount allowed preparation 2-(1,3-dimethylimidazolidinio)selenothiocarboxylate (19) red crystals. X-ray crystallographic analyses revealed...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFirst isolable dithiiranes: 3-(1,1,3,3-tetramethyl-4-oxo-4-phenylbutyl)-3-phenyldithiirane 1-oxidesAkihiko Ishii, Toru Akazawa, Meng Xin Ding, Takanari Honjo, Juzo Nakayama, Masamatsu Hoshino, and Motoo ShiroCite this: J. Am. Chem. Soc. 1993, 115, 11, 4914–4915Publication Date (Print):June 1, 1993Publication History Published online1 May 2002Published inissue 1 June 1993https://doi.org/10.1021/ja00064a072RIGHTS & PERMISSIONSArticle...
Abstract A new, convenient method for the synthesis of selenoketones has been reported. The reaction dimagnesium salts ketone hydrazones with diselenium dichloride affords an intermediate tentatively assigned as tetraselenides, which are converted into by heating in presence tributylamine. comparative study on reactions 1,1,3,3-tetramethyl-2-indanselone and corresponding thioketone Grignard organolithium reagents have carried out. Analysis products revealed that heterophilic attack...
A selenaplatinacycle (see structure 1; red P, blue Pt, green Se) is formed by the reactions of TripSe(O)SeTrip (Trip = 9-triptycyl) and TripSeOH with [Pt(PPh3)2(η2-C2H4)] intramolecular CH activation leading to cyclometalation. The reaction TripSeSeTrip also provided 1 together TripSeH, which reacts give hydrido selenolato platinum(II) complex 2.
The first examples of palladium(II) hydrido complexes having a dihydrosilyl or dihydrogermyl ligand, [PdH(EH2Trip)(dcpe)] (E = Si (2), Ge (4); dcpe 1,2-bis(dicyclohexylphosphino)ethane), were synthesized by oxidative addition an overcrowded primary silane and germane, TripEH3 (1), (3); Trip 9-triptycyl) with [(μ-dcpe)Pd]2 in toluene. molecular structures 2 4 established single-crystal X-ray analysis, which showed distorted-square-planar geometry around the palladium centers, probably due to...
trans-Cyclooctanediyl-bridged [OSSO]-type ligand 4 reacts with TiCl(4)(thf)(2) in toluene to produce the corresponding titanium(IV) dichloro complexes as an inseparable mixture of cis-α isomer 6a and cis-β 6b a ratio 2:1, whereas treatment dilithio salt TiCl(3)(thf)(3) Et(2)O afforded chloride-bridged dimeric titanium(III) complex 8, which indicated antiferromagnetic character nonpolar solvent solution. Di(isopropoxy) 10 having C(2)-symmetric configuration was synthesized by reaction...
Group 5 metal complexes bearing an [OSSO]-type bis(phenolate) ligand have been successfully prepared by the reaction of a bis(phenol) compound 3 or its dilithio salt 6 with VO(OPr)3, NbCl5, TaCl5. X-ray crystallographic analyses revealed monomeric nature resulting complexes, [OSSO]VO(OPr) (5), [OSSO]NbCl3 (7), and [OSSO]TaCl3 (8), where centers adopted cis-α configurations [OSSO] tetradentate ligand. The tantalum(V) complex 8 iBu3Al/(Ph3C)[B(C6F5)4] as activator catalyzed polymerization...
[OSSO]-type dibenzyl zirconium(IV) complexes 9 and 10 possessing aryl substituents ortho to the phenoxide moieties (ortho substituents, phenyl 2,6-dimethylphenyl (Dmp)) were synthesized characterized. Upon activation with dMAO (dried methylaluminoxane), complex was found promote highly isospecific styrene polymerizations ([mm] = 97.5%–99%) high molecular weights Mw up 181,000 g·mmol−1. When Dmp-substituted pre-catalyst 10/dMAO system used, highest activity, over 7700 g·mmol(10)−1·h−1,...
Silaimine exists in equilibrium with aminosilylene, the formation of which was confirmed using variable-temperature NMR experiments and a trapping reaction.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXT1-Adamantyl-tert-butyltetrathiolane 2,3-Dioxide: First Isolable vic-Disulfoxide and Efficient Precursor of S2OAkihiko Ishii, Masaaki Nakabayashi, Juzo NakayamaView Author Information Department Chemistry, Faculty Science Saitama University, Urawa, 338-8570, Japan Cite this: J. Am. Chem. Soc. 1999, 121, 34, 7959–7960Publication Date (Web):August 12, 1999Publication History Received13 May 1999Published online12 August inissue 1 September...