检索结果-南通市图书馆

Deuterated N-difluoromethylthiophthalimide:A stable,scalable reagent for radical and electrophilic deuteriodifluoromethylthiolations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第9期33卷 4293-4297页

作者： Chunyang Hu Fangming Chen Guo-Ping Lu Wen-Bin Yi School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Organofluorine Chemistry Shanghai Institute Organic ChemistryChinese Academy of SciencesShanghai 200032China

A new,stable and scalable reagent for deuteriodifluoromethylthiolation(deuterated N-difluoromethylthiophthalimide,PhthSCF_(2)D)has been developed.This reagent can be applied for the photocatalytic radical deuteriodifluoromethylthiolation of various olefins and aldehydes(30 examples).Meanwhile,it can achieve the electrophilic deuteriodifluoromethylthiolation of a series of electrophilic substrates including electron-rich arenes,aryl/vinylboronicacids,alkynes,amines,thiols andβ-ketoesters(22 examples).Some complex molecules can also be applied in both radical and electrophilic deuteriodifluoromethylthiolation using PhthSCF_(2)D as the reagent.

关键词： Deuteration Deuteriodifluoromethylthiolation Photocatalytic electrophilic Radical

Rational Design and Development of Low-Price, Scalable, Shelf-Stable and Broadly Applicable electrophilic Sulfonium Ylide-Based Trifluoromethylating Reagents

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2021年第6期39卷 1667-1682页

作者： Yafei Liu Yijing Ling Hangming Ge Long Lu Qilong Shen Key Laboratory of Orgonofluorine Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of Sciences345 Lingling RoadShanghai 200032China Shanghai Institute of Organic Chemistry Chinese Academy of Sciences345 Lingling RoodShanghai 200032China

The development of two highly reactive electrophilic trifluoromethylating reagents(trifluoromethyl)(4-nitrophenyl)bis(carbometh-oxy)methylide(1g)and(trifluoromethyl)(3-chlorophenyl)bis(carbomethoxy)methylide(1j)through structure-activity study was described.Under mild conditions,reagent 1g reacted with β-ketoesters and silyl enol ethers to give α-trifluoromethylated-β-ketoesters or α-trifluoromethylated ketones in high yields.In addition,reagent 1g could serve as a trifluoromethyl radical for a variety of trifluo-romethylative transformations under visible light irradiation,including radical trifluoromethylation of electron-rich indoles and pyrroles and sodium aryl sulfinates as well as trifluoromethylative difunctionalization with styrene derivatives.On the other hand,as a complimentary,under reductive coupling conditions,reagent 1j reacted with a variety of(hetero)aryl iodides for the formation of tri-fluoromethylated(hetero)arenes.

关键词： Fluorine Trifluoromethyl Ylides electrophilic Radicals

Isokinetic correlation analysis of the series of electrophilic substitution reactions of o-substituted phenylmercurials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2001年第2期44卷 182-190页

作者：王玉兰吴养洁 National Key Laboratory of Biochemical Engineering Institute of Chemical Metallurgy Chinese Academy of Sciences Beijing China Chemistry Department Zhengzhou University Zhengzhou China

Isokinetic relationships of the series of electrophilic substitution reactions of o-substi- tuted phenylmercurials are studied, and the results show, for the first time, that isokinetic correlation analysis can reveal the dominant factor in the system of the reactions. The analysis of SE2 of o-substituted phenylmercuric chlorides indicates that the steric effect of o-substituents is the pre-dominant factor when I2 is used as electrophilic agent, however, the electronic effect of o-substituents would become the predominant factor when HCl is used as the electrophilic agent. In SE1 of o-substituted phenylmercuric chlorides, the results of the analysis display that the predomi-nant factor is the field effects of o-substituents. The determination of predominant factors in those reactions would provide further scientific basis for those reaction mechanisms.

关键词： isokinetic correlation, dominant factor, electrophilic substitution, arylmercurials.

EHMO QUANTITATIVE VERIFICATION OF QUANTUM THEORY MECHANISM FOR electrophilic ADDITIONS

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1992年第9期37卷 732-737页

作者：戴乾圜刘荣华 Beijing Polytechnic University Beijing 100022 PRC

Most of the electrophilic additions on carbon-carbon multiply bond can be summarized as: where Y are certain atoms on the fight of the periodic table; Z may be null, atom or group. Regardless of the rate law of Ad_E2 Ad_E3 or the more complex kinetics, the micromechanisms of transition state of electrophilic addition can be divided into two sorts, i.e. open ion and bridged ion mechanisms. The former one allows free rotation of

关键词： mechanism of electrophilic addition stereospecificity regioselectivity orbital domination rule donoracceptor hybridization bond EHMO

Pentafluoroethylbenziodoxole （BIX-C2Fs）： A Shelf-Stable Reagent for Pentafluoroethylation of β-Ketoesters and Arylboronic Acids

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2016年第7期34卷 662-668页

作者： Jiansheng Zhu Yuguang Li Chuanfa Ni Qilong Shen Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organie Chemistry Chinese Academy of Sciences Shanghai 200032 China

An improved method for the preparation of pentafluoroethylating reagent pentafluoroethyl-substituted benzio- doxole （BIX-C2Fs） was described. Under mild conditions, BIX-C2F5 was able to react with β-ketoesters or a... 详细信息

关键词： fluorine pentafluoroethyl hypervalent electrophilic cross-coupling

Syntheses and Br…π supramolecular interactions in the crystal structure of ipriflavone bromides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2005年第4期48卷 315-325页

作者： ZHANG Zunting WANG Xiaobing School of Chemistry and Materials Science Shaanxi Normal UniversityXi'an 710062China School of Chemistry and Materials ScienceShaanxi Normal UniversityXi'an 710062China

Two novel compounds,3,8-dibromo-2-methoxyl-7-isopropoxyisoflavanone (1) and 3,6-dibromo-2-methoxyl-7-isopropoxyisoflavanone (2),are synthesized via bromination reaction of their precursor ipriflavone in methanol.The mixture of 1 and 2 co-crystallizes in ethanol and forms two different crystal shapes,the shape of 1 being block and 2 prism,they can be separated manually.1 and 2 are characterized by IR,1H NMR and single crystal X-ray diffraction.The mechanism of bromination reaction is also discussed.1 crystallizes in the monoclinic space group P 21/n with cell parameters a = 1.3569(3) nm,b = 0.6706(2) nm,c = 2.0704(4) nm,?= 97.50(2)°,V = 1.8678(6) nm3,Z = 4,Dc = 1.672 Mg/m3,R = 0.0455,wR = 0.0779,F(000) = 936.2 crystallizes in the monoclinic space group P 21/c with cell parameters a =1.3854(17) nm,b = 1.1215(14) nm,c = 1.3038(17) nm,? = 103.71(2)°,V = 1.968(4) nm3,Z = 4,Dc = 1.587 Mg/m3,R = 0.0306,wR = 0.0619,F(000) = 936.The Br…p interactions,hydrogen bonds,aromatic hy-drogen bonds and aromatic stacking interactions exist in the crystal structures of 1 and 2,which lead them into supramolecular compounds with a three-dimensional network structure,respec-tively.1 and 2 are the isoflavanone derivatives halogenated at C3 and this kind of isoflavanone halides has not been reported yet.

关键词： ipriflavone, bromine, electrophilic addition, crystal structure, isoflavanone, supramolecular interaction.

Some interesting CH_2CH_3 spin systems in several diethyl malonate indene derivatives studied with NMR and molecular modeling

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2009年第7期52卷 937-942页

作者： ZHANG Long1, HE WeiWei1, LIANG YongMin2 & CUI YuXin1 1 State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China 2 State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, China State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical Sciences Peking University Beijing China State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou China

While studying the electrophilic cyclization of acetylenic malonates in synthesizing malonate indene derivatives with high regio and stereo-selectivity, we found that the CH2 and CH3 protons of two COOCH2CH3 groups in some diethyl malonate indene derivatives showed very interesting spin-spin coupling and signal multiplicity. To explain those phenomena, we synthesized several diethyl malonate indene derivatives, and then used 1H NMR spectra and molecular modeling to investigate the CH2CH3 spin system of these two COOCH2CH3 groups in detail. The results showed that the spin systems of CH3CH2 of the two COOCH2CH3 groups in those compounds may exist in different froms (AMX3, ABX3 and A2X3), and the effect of the aromatic ring induced by the phenyl group at the end of the triple bond is the main reason responsible for those phenomena.

关键词： electrophilic cyclization spin-spin coupling signal multiplicity molecular modeling spin system aromatic ring

RESEARCH OF STEREOCHEMISTRY ON PRINS REACTION OF CYCLOHEXENE

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1989年第24期34卷 2045-2049页

作者：戴乾圜刘荣华李运香 Beijing Polytechnic University. Beijing 100022 PRC

The Prins reaction between most olefins and formaldehyde shows non-stereospecificity and region selectivity. All the additions of halostyrene, cyclopentene and other olefms are conducted through open ion mechanism. However, the Prins reaction of cyclohexene with water or acetic acid as solvent gives the trans-product stereospecifically with excellent yield. It is considered that the Prins reaction of cyclohexene different from the addition of other

关键词： mechanism of electrophilic addition orbital domination rule Prins reaction NMR basketed solvent effect donor-acceptor bond.

Synthesis and Microbial Studies of New Pyridine Derivatives-Ill

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2007年第9期25卷 1363-1369页

作者： PATEL, N. B. AGRAVAT, S. N. Department of Chemistry Veer Narmad South Gujarat University Surat-395 007 Gujarat India

2-Amino substituted benzothiazole 4a--4I and p-acetamidobenzenesulfonyl chloride 2 were used to prepare 2-（p-aminophenylsulfonamido） substituted benzothiazole 6a--6I using mixture of pyridine and acetic anhydride which formed an electrophilic complex （N-acetyl pyridinium） to facilitate condensation to give desired product by removal of HC1. 2-{p-[（3-Carboxypyrid-2-y1）amino]phenylsulfonamido}benzothiazoles 8a--81 were synthesized from 2-chloropyridine-3-carboxylic acid 7 and 6a--6I in 2-ethoxy ethanol using Cu-powder and K2CO3. Acid chlorides 9a--91 were condensed with 2-hydroxyethyl piperazine 10 and 2,3-dichloropiperazine 11 for amide deriva- tives 2-（p-（（3-（4-（2-hydroxyethy1）piperazin-1-ylcarbonyl）pyrid-2-y1）amino）phenylsulfonamido）benzothiazoes 12a -121 and 2-{p-[3-（2,3-dichloropiperazin-l-ylcarbonyl）pyrid-2-ylamino]phenylsulfonamido}benzothiazoles 13a- 131 respectively. The structures of the new compounds have been established on the basis of their chemical analysis and spectral data （IR, 1↑H NMR and mass）. All the compounds have been screened for their antibacterial and antifungal activities.

关键词： 2-amino substituted benzothiazole antimicrobial 2-chloropyridine-3-carboxylic acid electrophilic 2-ethoxyethanol