共查询到20条相似文献,搜索用时 15 毫秒
1.
An efficient procedure for conversion of alcohols to the corresponding carbonyl compounds, an alternative to the classical Swern oxidation, is described. Pivaloyl chloride is employed as a mild and inexpensive electrophile. A possible reaction mechanism is proposed. 相似文献
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Praneshwar Sethupathy Inas M. Alnashef John R. Monnier Michael A. Matthews John W. Weidner 《合成通讯》2013,43(24):3632-3647
Abstract We show that the superoxide ion (O2 ??) generated electrochemically from oxygen dissolved in room-temperature ionic liquids (RTILs) reacts with primary and secondary alcohols to form the corresponding ketones and carboxylic acids, respectively. Specifically, we study the conversion of benzhydrol to benzophenone and benzyl alcohol to benzaldehyde/benzoic acid. The kinetics (e.g., rate, selectivity, and yield) for these reactions are also determined as functions of the variations in the structure of the ionic liquids. The RTILs used here are imidazolium-based cations where the functional groups on the imidazolium ring are modified. Specifically, 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6], 1-butyl-2,3-dimethylimidazolium hexafluorophosphate [bdmim][PF6], and 1-hexyl-3-methylimidazolium hexafluorophosphate [hmim][PF6] are used as the reaction medium. These results are compared to an ammonium-based RTIL (N-butyl-N-trimethylammonium bis(trifluoromethylsulfonyl)imide). The results show that the nucleophilic attack by the O2 ?? of both the RTIL and the alcohol, especially that of the H atom at the R2 position of the [bmim][PF6] and [hmim][PF6], greatly affects the yields. No RTIL degradation products were detected for the reactions in [bdmim][PF6] and N-butyl-N-trimethylammonium bis(trifluoromethylsulfonyl)imide ionic liquids. For the benzyl alcohol oxidation reaction in the RTIL, N-butyl-N-trimethylammonium bis(trifluoromethylsulfonyl)imide, benzaldehyde formed did not undergo further oxidation to form benzoic acid, which may be due to the greater hydrophobicity of this RTIL. The competitive reaction kinetics between the alcohol and RTIL component must be considered in the selection of the RTIL solvent system. 相似文献
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Dr. Dong Zheng Dr. Qiang Wang Dr. Hung‐Sui Lee Dr. Xiao‐Qing Yang Prof. Deyang Qu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(26):8679-8683
Tris(pentafluorophenyl)borane (TPFPB) was found to be an efficient catalyst for rapid superoxide (O2?) disproportionation. The kinetics for the catalytic disproportionation reaction is much faster than the reaction between O2? and propylene carbonate. Therefore, the negative impact of the reaction between the electrolyte and O2? produced by the O2 reduction is minimized. The cathodic current for O2 reduction can be doubled in the presence of TPFPB. The high reduction current resulted from the pseudo two‐electron O2‐reduction reaction due to the replenishment of O2 at the electrode surface. This discovery could lead to a new avenue for the development of high‐capacity, high‐rate, rechargeable Li–air batteries. 相似文献
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Doria S. Badawy Ebrahim Abdel-Galil Ezzat M. Kandeel Wahid M. Basyouni Tamer K. Khatab 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2799-2812
A combination of tetrachlorosilane and zinc chloride in dichloromethane as an efficient and ambient binary reagent to promote a one-pot amidoalkylation reaction of enolizable ketones, aromatic aldehydes with acetonitriles, or benzonitrile have been developed. The newly synthesized β-acetamidoketones 3 and β-benzamidoketones 5 were obtained in good yields. 相似文献
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高分子絮凝剂在水处理技术中占有十分重要的地位,而且已成为目前废水处理中的一类不可缺少的重要试剂。本文介绍了高分子絮凝剂的絮凝机理、种类、性质及其应用。 相似文献
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用新中间体合成头孢曲松钠 总被引:1,自引:0,他引:1
以二乙基硫代磷酰-(Z)-(2-氨基噻唑4-基)-甲氧酰胺-乙酸钠盐为中间体合成了头孢曲松钠,收率94.77%。保存2年后头孢曲松钠的含量平均下降0.4%,色级平均下降0.5号,质量稳定性较好。 相似文献
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Farhad Shirini Mohammad Ali Zolfigol Mahroo Khaleghi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1999-2002
A variety of alcohols underwent acetylation with acetic anhydride in the presence of silica chloride. All reactions were performed at room temperature and under completely heterogeneous conditions in good to high yields. 相似文献
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Dr. Dong-Dong Liang Dieuwertje E. Streefkerk Daan Jordaan Jorden Wagemakers Dr. Jacob Baggerman Prof. Dr. Han Zuilhof 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(19):7564-7570
SuFEx reactions, in which an S−F moiety reacts with a silyl-protected phenol, have been developed as powerful click reactions. In the current paper we open up the potential of SuFEx reactions as enantioselective reactions, analyze the role of Si and outline the mechanism of this reaction. As a result, fast, high-yielding, “Si-free” and enantiospecific SuFEx reactions of sulfonimidoyl fluorides have been developed, and their mechanism shown, by both experimental and theoretical methods, to yield chiral products. 相似文献
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CHEN Zhen ** ZHENG Xi CHEN Ri-yao LAN Rui-fang LIN Zhi-hong CHEN Yu-feng Experiment Center Fujian Normal University Fuzhou P. R. ChinaZHANG Yi-kangLinyi Normal College Linyi P. R. China 《高等学校化学研究》2002,18(1):34-37
IntroductionAs is known,textile wastewater is a troubleindustrial wastewater due to its environment pollu-tion caused by its deep color,huge amounts,highCODcrand BOD5,as well as itsdifficultdegradationby biodegradation[1— 3 ] .Fenton reagent[4— 6] has a high redox potential,2 .8V. Recently,the Fenton reagent used as anoxidant to treat toxic organic wastewater such aswood glue,lead trinitroresorcinate and textilewastewater has been reported.Although hydroxylradical can be generated by a c… 相似文献
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The new reagent, quinolinium bromochromate (QBC), apart from being efficient as an oxidant for alcohols, also functions as a good brominating agent for aromatic compounds. 相似文献
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The new reagent, benzimidazolium bromochromate (BIBC), apart from being efficient as an oxidant for alcohols, also functions as a good brominating agent for aromatic compounds. 相似文献
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Biotinylamidopropylammonium trifluoroacetate was obtained by acylation of 4-(tert-butyloxycarbonylamino)propylamine, followed by removal of the protective group. Consequently, it was found to be useful for the development of effective immunoassays. 相似文献
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Mahmood Tajbakhsh Majid M. Heravi Farajollah Mohanazadeh Siavosh Sarabi Mitra Ghassemzadeh 《Monatshefte für Chemie / Chemical Monthly》2001,132(10):1229-1231
Summary. N-Methylpiperidinium chlorochromate adsorbed on alumina was found to be an efficient and selective reagent for the mild oxidative
cleavage of oximes.
Received March 1, 2001. Accepted March 22, 2001 相似文献
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Mahmood Tajbakhsh Majid M. Heravi Farajollah Mohanazadeh Siavosh Sarabi Mitra Ghassemzadeh 《Monatshefte für Chemie / Chemical Monthly》2001,45(6):1229-1231
N-Methylpiperidinium chlorochromate adsorbed on alumina was found to be an efficient and selective reagent for the mild oxidative
cleavage of oximes. 相似文献
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Jeffrey Schwartz Jay A. Labinger 《Angewandte Chemie (International ed. in English)》1976,15(6):333-340
Hydrozirconation has recently been developed as a procedure for functionalizing alkenes, alkynes, and 1,3-dienes via organozirconium(IV) intermediates. These intermediates react with a variety of electrophilic reagents to give organic products in high yield. Mechanisms of reactions involved in these sequences are discussed. 相似文献
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