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排序方式: 共有229条查询结果,搜索用时 15 毫秒
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Ryu Sato Katsumi Araya Yuji Takikawa Saburo Takizawa Shigeru Oae 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):245-247
Abstract Although numerous investigations on the chemistry of organic sulfenamides, for example, studies on the S–N torsional barrier,1 the electronic nature of the S–N bond2 and some nucleophilic substitutions on sulfur or nitrogen atom3 have been known, no example of nucleophilic substitution on arylcarbon of aromatic sulfenamides has been reported. 相似文献
224.
Ryu Sato Takehiko Goto Kazuo Kakuta Yuji Takikawa Saburo Takizawa Shigeru Oae 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):289-294
Abstract α-Chlorotoluene (1) reacts with elemental sulfur in liquid ammonia affording dibenzyl disulfide (2), dibenzyl trisulfide (3), dibenzyl tetrasulfide (4), dibenzyl pentasulfide (5) and benzylidene benzylimide (6) at a low temperature such as 20°C. This reaction is presumed to be initiated by the nucleophilic attack of ammonium thioaminohydroxylate, “H2NS-NH4 +,” or dithioaminohydroxylate, “H2NSS-NH4,” formed upon treating elemental sulfur in liquid ammonia, on α-chlorotoluene (1). Benzylidene benzylimide (6) is presumed to be formed from benzylamine, which can be formed by treatment of α-chlorotoluene (1) with ammonia. 相似文献
225.
Satavisha Kayal Jun Kikuchi Naoya Shinagawa Shigenobu Umemiya Masahiro Terada 《Chemical science》2022,13(33):9607
A highly efficient kinetic resolution (KR) of racemic tertiary allylic alcohols was achieved through an intramolecular allylic substitution reaction using a co-catalyst system composed of chiral bisphosphoric acid and silver carbonate. This reaction afforded enantioenriched diene monoepoxides along with the recovery of tertiary allylic alcohols in a highly enantioselective manner, realizing an extremely high s-factor in most cases. The present method provides a new access to enantioenriched tertiary allylic alcohols, multifunctional compounds that are applicable for further synthetic manipulations.A highly efficient KR of racemic tertiary allylic alcohols was developed through the intramolecular SN2′ reaction using the chiral bisphosphoric acid/silver carbonate co-catalyst system, affording cis-epoxides and recovered alcohols in a high s-factor. 相似文献
226.
Islam Md. Rafiqul Kazuaki Shimada Shigenobu Aoyagi Yuji Takikawa Chizuko Kabuto 《Heteroatom Chemistry》2004,15(2):175-186
5H-1,2,4-oxathiazoles were efficiently synthesized from 6H-1,3,5-oxathiazine S-oxides by thermal cycloreversion of the substrates and the products were effectively converted into 1,2,4-thiadiazoles. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:175–186, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20004 相似文献
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Keisuke Shigenobu Taku Sudoh Junichi Murai Kaoru Dokko Masayoshi Watanabe Kazuhide Ueno 《Chemical record (New York, N.Y.)》2023,23(8):e202200301
Highly concentrated electrolytes (HCEs) have a similarity to ionic liquids (ILs) in high ionic nature, and indeed some of HECs are found to behave like an IL. HCEs have attracted considerable attention as prospective candidates for electrolyte materials in future lithium secondary batteries owing to their favorable properties both in the bulk and at the electrochemical interface. In this study, we highlight the effects of the solvent, counter anion, and diluent of HCEs on the Li+ ion coordination structure and transport properties (e. g., ionic conductivity and apparent Li+ ion transference number measured under anion-blocking conditions, ). Our studies on dynamic ion correlations unveiled the difference in the ion conduction mechanisms in HCEs and their intimate relevance to values. Our systematic analysis of the transport properties of HCEs also suggests the need for a compromise to simultaneously achieve high ionic conductivity and high values. 相似文献
229.
Islam Md. Rafiqul Kazuaki Shimada Shigenobu Aoyagi Yoriko Fujisawa Yuji Takikawa 《Heteroatom Chemistry》2004,15(3):208-215
Treatment of 6H-1,3,5-oxathiazine S-oxides by Lawesson's reagent (LR) at high temperature furnished 3H-1,2,4-dithiazoles in moderate to good yields. Deoxygenation of 6H-1,3,5-oxathiazine S-oxides was performed by LR in the presence of EtOH. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:208–215, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20011 相似文献