Miki Murata
Kitami Institute of Technology
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Featured researches published by Miki Murata.
Tetrahedron Letters | 1999
Miki Murata; Shinji Watanabe; Yuzuru Masuda
Abstract The treatment of pinacolborane with vinylarenes in the presence of a catalytic amount of [RhCl(cod)] 2 , through a dehydrogenative borylation, provides pinacol esters of ( E )-2-arylethenylboronates.
Tetrahedron Letters | 2000
Miki Murata; Shinji Watanabe; Yuzuru Masuda
Abstract Various allyl halides were borylated with pinacolboranes in the presence of NEt 3 and a catalytic amount of Pt(dba) 2 and AsPh 3 to afford regio- and stereodefined allylboranes in good yields.
Tetrahedron Letters | 1999
Miki Murata; Shinji Watanabe; Yuzuru Masuda
Abstract Various alkenyl iodides were silylated with hydrosilanes in the presence of KOAc and a catalytic amount of Pd 2 (dba) 3 ·CHCl 3 to afford the corresponding regio- and stereodefined ( E )-alkenylsilanes in high yields.
Macromolecular Rapid Communications | 2000
Shinji Watanabe; Kenji Ueno; Kazuhiko Kudoh; Miki Murata; Yuzuru Masuda
Dispersion polymerization of styrene (S) and vinylbenzyltrimethylammonium chloride (VBA) was conducted in an ethanol-water medium using an aromatic poly(amic acid) (PAA) as the stabilizer. When equimolar amounts of VBA and the carboxylic acid of PAA were used, monodisperse particles with high PAA content were obtained quantitatively. The imidization of PAA on the particles proceeded with acetic anhydride and N,N-dimethylaminopyridine to form core-shell PS-polyimide particles.
Synthetic Communications | 2002
Miki Murata; Takashi Oyama; Shinji Watanabe; Yuzuru Masuda
ABSTRACT Various benzyl halides were borylated with pinacolborane in the presence of i Pr2NEt and a catalytic amount of PdCl2(PPh3)2 to afford the corresponding benzylboronates in good yields.
Heterocycles | 2010
Miki Murata; Tomoko Sambommatsu; Takeshi Oda; Shinji Watanabe; Yuzuru Masuda
The borylation of electron-deficient aryl chlorides with pinacolborane proceeded in the presence of Bu 4 NI and a catalytic amount of Pd(dba) 2 / bis(2-di-tert-butylphosphinophenyl) ether. The combination of NiCl 2 (dppp) catalyst and Bu 4 NBr was also efficient for the borylation of aryl chlorides.
Chemcatchem | 2016
Kazumasa Kon; Hiroyuki Suzuki; Kosuke Takada; Yoshihito Kohari; Takeshi Namikoshi; Shinji Watanabe; Miki Murata
The Ru‐catalyzed dehydrogenative silylation of 2‐alkyloxazolines with 1,1,1,3,5,5,5‐heptamethyltrisiloxane took place site‐selectively at methyl C(sp3)−H bonds located γ to the nitrogen atom of the oxazolyl groups. Pyridine and pyrazole rings could also be used as a directing group. A catalytic mechanism based upon successive σ‐bond metathesis is proposed.
Chemcatchem | 2015
Shinsuke Okada; Takeshi Namikoshi; Shinji Watanabe; Miki Murata
The ruthenium‐catalyzed dehydrogenative borylation of 2‐arylpyridines with pinacolborane took place at ortho‐positions of the benzene ring. Density functional theory calculations and kinetic isotope effect experiments suggest that the catalytic cycle should involve oxidative addition of the CH bond, the rate‐determining σ‐bond metathesis of pinacolborane with the ruthenium hydride complex, and reductive elimination of the CB bond.
Journal of Synthetic Organic Chemistry Japan | 2010
Miki Murata; Yuzuru Masuda
Since arylsilanes are versatile reagents for carbon-carbon bond formation, the supply of functionalized and reactive arylsilanes has become more necessary. We demonstrated the first example of the palladium(0)-catalyzed silylation of aryl halides with triethoxysilane as a silicon source and affording the corresponding aryltriethoxysilanes. Although this catalyst system has lacked the wide applicability to functionalized substrates, we found that a rhodium(I) complex overcomes a number of limitations of the palladium(0)-catalyzed silylation. The silylation of aryl iodides with hydrosilanes was able to apply to 1,1,1,3,5,5,5-heptamethyltrisiloxane by the appropriate choice of catalyst systems. 3-Aryl-1,1,1,3,5,5,5-heptamethyltrisiloxanes were also provided by platinum-catalyzed dehydrogenative coupling with aromatic hydrocarbons. These catalytic silylations supply a wide range of functionalized arylsiloxanes.
High Performance Polymers | 2001
Shinji Watanabe; Taizoh Yamamoto; Miki Murata; Yuzuru Masuda
New soluble polyimides with inherent viscosities of 0.25–0.62 dl g−1 were synthesized from 3,6-diamino-9-alkylcarbazole and various aromatic tetracarboxylic dianhydrides by the conventional two-step method, including ring-opening polyaddition and subsequent thermally cyclodehydration. Most of the polyimides having hexyl alkyl chains were soluble in N-methylpyrrolidinone and m-cresol, while the polymers having ethyl chains were not soluble in organic solvents. The glass transition temperatures and 10% weight loss temperatures under argon of the polyimides having hexyl chains were in the ranges 232–269 °C and 485–518 °C, respectively.