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71.
Yasumitsu Tamura Yasuyoshi Miki Masazumi Ideda 《Journal of heterocyclic chemistry》1973,10(4):447-450
The syntheses and some reaetions of N,N'-diamino-2,2′- and 4,4′-bipyridinium salts (IV, V and VI) are described. These compounds are prepared by the reaction of bipyridyls (I-III) with O-mesitylenesulfonylhydroxylamine in moderate to good yields. Compounds IV and VI were found to give the N,N'-diacyl derivatives by the reaction with acyl chlorides and to undergo 1,.3-dipolar cycloaddition reaction with an acetylenic compound to give 1:2 adducts. Photo-irradiation of N,N'-dibenzoylimino-2,2′-bipyridinium betaine (IX) isomerizes to a mono diazepine derivative (XVI). 相似文献
72.
Yasumitsu Tamura Joong-Hyup Kim Yasuyoshi Miki Hironori Hayashi Masazumi Ikeda 《Journal of heterocyclic chemistry》1975,12(3):481-483
New routes to the v-triazolo[1,5-a]pyridine and pyrazolo[1,5-a]pyridine ring systems are described. Treatment of the N-amine salts of 2-picolinealdehyde oxime or 2-pyridyl ketone oximes with polyphosphoric acid gave v-triazolo[1,5-a]pyridines in fair yields. Treatment of 2-picolyl ketones or their oximes with O-mesitylenesulfonylhydroxylamine produced directly pyrazolo-[1,5-a]pyridines. These reactions were extended to the quinoline cases. 相似文献
73.
Yasumitsu Tamura Hironori Hayashi Masazumi Ikeda 《Journal of heterocyclic chemistry》1975,12(5):819-823
3-Acylimino-1-methylbenzimidazolium betaines undergo 1,3-dipolar cycloaddition reactions with activated alkenes (methyl acrylate, acrylonitrile, and fumaronitrile) and methyl propiolate to produce 2-substituted 1-methylbenzimidazoles. The transformation involves the initial formation of a 1,3-dipolar cycloadduct followed by the N? N bond cleavage. The primary adducts can be isolated from the reaction with methyl acrylate and acrylonitrile. 相似文献
74.
Hironori Sato Yasumitsu Uraki Takao Kishimoto Yoshihiro Sano 《Cellulose (London, England)》2003,10(4):397-404
To explore further potential applications of acetic acid pulp, an investigation was conducted to develop a direct method for producing cellulose acetate from wood in combination with atmospheric acetic acid pulping. The process consists of delignification, totally chlorine-free bleaching, and esterification, with the concentrated acetic acid aqueous solution being used as only solvent throughout the process. The acetic acid pulp with kappa number of 30 and ISO brightness of 16 was bleached with 5% ozone on pulp to kappa number of 1.4 and brightness of 61. The resulting bleached pulp was further bleached with peracetic acid to kappa number of less than 1.0 and brightness of 68. The final bleached acetic acid pulp was acetylated with acetic anhydride in the concentrated acetic acid for 45 min to produce cellulose acetate with an apparent degree of substitution (DS) of 2.54. Although the product was lower grade compared with commercially available cellulose diacetate because it was prepared from the chemical pulp but not dissolving pulp, the product was almost soluble in acetone. Eventually, the DS of the acetone-soluble fraction was 2.62. The acetone solubility might be attributed to the original acetic acid pulp that had been partially acetylated during the pulping. 相似文献
75.
Yasumitsu Tamura Ling Ching Chen Masanobu Fujita Yasuyuki Kita 《Journal of heterocyclic chemistry》1980,17(1):1-4
The Synthesis of novel 1-substituted 3-anilino-4-diethylaminomethyl-5-oxo-3,4-dehydro-piperidines and 2-substituted 1,2,3,5,6,11-hexahydro-5-phenyl-4H-pyrido[3,4-b][1,5]benzo diazepin-4-ones from the β-arylaminovinylketones derived from N-substituted piperidine-3,5-diones is described. 相似文献
76.
Md. Ibrahim H. Mondal Yasumitsu Uraki Makoto Ubukata Koki Itoyama 《Cellulose (London, England)》2008,15(4):581-592
The influence of treating cotton fibres with several amines on the mechanical properties, moisture sorption ability before
and after graft polymerization, and on graft yields for various water-soluble and water-insoluble vinyl monomers were analysed.
As compared to water, the treatment with amines, ethylenediamine (EDA) in particular, resulted in a decrease in the crystallinity
and tensile strength of the cotton fibres, and an increase in the moisture sorption. The graft yields of amine-treated cotton
fibres using water-soluble monomers, acrylic acid (AA), methacrylic acid (MAA) and acrylamide (AM) were greater than those
observed for water-treated cotton fibres, whereas the graft yields using water-insoluble monomers, methyl acrylate (MA), methyl
methacrylate (MMA) and vinyl acetate (VA) were lower. The moisture sorption ability was improved by the graft polymerization
with water-soluble monomers. The improvement was enhanced for MA and MAA by treatment with sodium hydroxide to form the corresponding
sodium carboxylate derivatives. The tensile strength of EDA-treated cotton was slightly reduced by grafting, while that of
the water-activated cotton yarn was barely changed. These results suggest that the graft polymerization of amine-treated cotton
fibres with certain vinyl monomers increased the moisture sorption ability without resulting in increased fibre rigidity. 相似文献
77.
78.
Yoshinori Tominaga Satoshi Takada Shinya Kohra Yasumitsu Shigemitsu 《Journal of heterocyclic chemistry》2001,38(5):1143-1151
3‐[(Trimethylsilylmethylamino)(methylthio)]methylene‐2‐coumaranone ( 4a ) and 1‐methyloxindole ( 4b ), readily prepared by reactions of the corresponding bis(methylthio)methylene heterocyclic compounds ( 2a, b ), with (trimethylsilylmethyl)amine (3), were found to be synthetic equivalents of heterocyclic alkylidene‐azomethine ylides. Reactions of 4a, b with reactive heterodipolarophiles such as aldehydes and ketones and reactive alkenes in the presence of cesium fluoride gave the 1,3‐dipolar cycloadducts, 3‐(2‐oxazoli‐dinylidene)‐oxindole and ‐coumaran‐2‐one derivatives ( 8a‐j, 9a‐h ), as well as pyrrolylidenecoumaran‐2‐one and oxindole derivatives ( 12‐15,17,18 ), via the 1,3‐elimination of (methylthio)trimethylsilane. 相似文献
79.
Size‐Selective Complexation and Extraction of Endohedral Metallofullerenes with Cycloparaphenylene 下载免费PDF全文
Yusuke Nakanishi Dr. Haruka Omachi Sanae Matsuura Prof. Dr. Yasumitsu Miyata Prof. Dr. Ryo Kitaura Prof. Dr. Yasutomo Segawa Prof. Dr. Kenichiro Itami Prof. Dr. Hisanori Shinohara 《Angewandte Chemie (International ed. in English)》2014,53(12):3102-3106
A new strategy for the non‐chromatographic extraction of metallofullerenes from solutions of arc‐processed raw soot is based on the size‐selective complexation with cycloparaphenylene (CPP). [11]CPP has a high affinity for Mx@C82 (x=1, 2); for example, Gd@C82 can be selectively extracted from a fullerene mixture by the addition of [11]CPP. This approach should open new opportunities in metallofullerene chemistry, including for the bulk extraction of metallofullerenes. 相似文献
80.
Dr. Jinying Zhang Zhen Zhu Prof. Dr. Yanquan Feng Hitoshi Ishiwata Dr. Yasumitsu Miyata Dr. Ryo Kitaura Dr. Jeremy E. P. Dahl Prof. Dr. Robert M. K. Carlson Dr. Natalie A. Fokina Prof. Dr. Peter R. Schreiner Prof. Dr. David Tománek Prof. Dr. Hisanori Shinohara 《Angewandte Chemie (International ed. in English)》2013,52(13):3717-3721