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reagent types and action mechanisms in ilmenite flotation:A review

International Journal of Minerals,Metallurgy and Materials 2022年第9期29卷 1656-1669页

作者： Jiaozhong Cai Jiushuai Deng Liang Wang Mingzhen Hu Hongxiang Xu Xiaoan Hou Bozeng Wu Shimei Li School of Chemical and Environmental Engineering China University of Mining and Technology(Beijing)Beijing 100083China ZHONGGUANCUN Green Mine Industry Alliance Beijing 100083China Liuzhou China-Tin Nonferrous Design and Research Institute Co. Ltd.CHINA TIN GROUPLiuzhou 545006China State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resource EngineeringKunming University of Science and TechnologyKunming 650093China

Ilmenite is an essential mineral for the extraction of titanium.Conventional physical separation methods have difficulty recovering fine ilmenite,and dressing plants have begun applying flotation to recover ilmenite.The interaction of reagent groups with Ti and Fe sites on the ilmenite surface dramatically influences the ilmenite flotation.However,the investigation on Fe sites has received more attention because the activity of Ti is lower than that of Fe.For the activators on ilmenite flotation,most are metal ions but typically lead ions.The metal ions of activators promote ilmenite flotation by increasing the active sites on the ilmenite surface.Combined reagents have a better selective separation of ilmenite than single reagents due to their synergistic effect.Combining the lead ion(Pb^(2+))and the benzyl hydroxamic acid(BHA)into a Pb-BHA complex has a marked effect on ilmenite flotation,which puts forward a new idea of developing combined reagents for ilmenite flotation.This review considers reagent types and action mechanisms in ilmenite flotation.On the basis of the analysis of previous research,a brief future outlook of reagent types and action mechanisms in ilmenite flotation is also proposed in this study.

关键词： ilmenite flotation reagent action mechanism combined reagents

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Lawesson’s reagent-promoted deoxygenation of γ-hydroxylactams or succinimides for the syntheses of substituted pyrroles

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Organic Chemistry Frontiers 2022年第6期9卷 1599-1603页

作者： Tao Shi Xiaodong Wang Gaofeng Yin Zhen Wang School of Pharmacy Lanzhou UniversityNo 199 West Donggang RoadLanzhouChina School of Pharmaceutical Science Hengyang Medical SchoolUniversity of South ChinaHengyang 421001HunanChina

A new method of Lawesson’s reagent-promoted deoxygenation of γ-hydroxypyrrolidones or succinimides was developed for synthesizing substituted pyrroles with 92 examples displayed. This reaction features simple operation, satisfactory yields, wide substrate scope, and excellent functional group tolerance.This robust protocol has been successfully applied in the expeditious syntheses of the key intermediate ofStemona alkaloids.

关键词： substituted reagent promoted

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Electrophilic N-trifluoromethylthiophthalimide as a fluorinated reagent in the synthesis of acyl fluorides

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Organic Chemistry Frontiers 2022年第2期9卷 342-346页

作者： Chen Zhu Serik Zhumagazy Huifeng Yue Magnus Rueping KAUST Catalysis Center(KCC) King Abdullah University of Science and Technology(KAUST)Thuwal23955-6900Saudi Arabia

Herein we report the deoxygenated fluorination of readily available carboxylic acids.A series of acyl fluorides have been synthesized using shelf-stable N-trifluoromethylthiophthalimide as a fluorinated reagent for the first time.Scale-up reactions and sequential cross-couplings were performed successfully to demonstrate the practicability of this fluorination protocol.

关键词： reagent synthesis readily

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A bench-stable reagent for C-4 selective deuteriodifluoromethylation of azines

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Chinese Chemical Letters 2022年第11期33卷 4817-4821页

作者： Junqing Liang Lefeng Dong Feng Qian Yijin Kong Mingxia Wang Xiaoyong Xu Xusheng Shao Zhong Li Shanghai Key Laboratory of Chemical Biology School of PharmacyEast China University of Science and TechnologyShanghai 200237China Research Center of Analysis and Test School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Deuteriodifluoromethyl(CF_(2)D)is a challenging and important functional group due to difficult deuterium incorporation and lack of effective precursor reagents.Herein,we report a bench-stable reagent,deuteriodifluoromethyl phosphine(DDFP)from cheap deuterium source for selectivity deuteriodifluoromethylation of azines with a high deuterium incorporation yield.The late-stage modification of complex molecules further confirmed the potential of this reagent for practical applications.We expect that our reagent to find applications in synthesis of isotope-labelled molecules of interests for drug-discovery and related ilucidation of mechanism of action.

关键词： reagent Deuterium Difluoromethylation C-4 selective Azines

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reagent Vibration Effect on the Stereodynamics for the C+CD→C2+D Reaction

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Chinese Physics Letters 2011年第11期28卷 95-98页

作者：解廷献石英 School of Science Dalian Jiaotong UniversityDalian 116028 Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012

We study the effect of the reagent vibration of the CD on the stereodynamics of the C+CD→C2+D reaction by using the quasi-classical trajectory method at a collision energy of 2.306 kcal/mol on the potential energy surface of the 12𝐴′state[Boggio-Pasqua et al.Mol.Phys.98(2000)1925].The vector correlation distributions𝑝(θr)and the dihedral-angle distribution𝑝(Φr)as well as𝑝(θr,Φr)are calculated.In addition,two polarizationdependent generalized differential cross sections of the product are presented and discussed within a center-ofmass framework.The results show that the effect of reagent vibration can cause obviously different effects on the stereodynamics of the title reaction.

关键词： reaction dynamics reagent

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S-Trifluoroethyl Benzenesulfonothioate:A Bench-Stable reagent for Electrophilic Trifluoroethylthiolation

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Chinese Journal of Chemistry 2020年第12期38卷 1625-1628页

作者： Shuai Huang Ziheng Xi Kui Lu Haifeng Lu Chen-Ho Tung Zhenghu Xu Key Lab for Colloid and Interface Chemistry of Education Ministry Shandong UniversityJlinanShandong 250100China Stote Key Laborctory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of SciencesShanghai 200032China Land Surveying and Mapping Institute of Shandong Province JinanShandong 250013China

of main observation and conclusion We report herein a practical approach for synthesis of an electrophilic trifluoroethylthiolation reagent PhSO2SCH2CF3(1)from easily available materials.The reaction proceeded through a protonation and nucleophilic substitution cascade of the in situ formed trifluorodiazoethane.This bench-stable reagent could easily be applied to introduce trifluoroethylthio group into small organic molecules.

关键词： materials. reagent substitution

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Double dehydrogenation of carbocyclic β-dicarbonyl compounds:Koser's reagent can do what iodine(V) reagents can

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Science China Chemistry 2019年第5期62卷 597-601页

作者： Shan-Shan Liu Li Wang Ya-Nan Duan Ao Yu Chi Zhang State Key Laboratory of Elemento-Organic Chemistry Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)College of ChemistryNankai University Department of Chemical Engineering and Safety Binzhou University Central Laboratory College of ChemistryNankai University

Koser's reagent is found to be effective in the oxidative double dehydrogenation of various carbocyclic β-dicarbonyl compounds,which constitutes the first example on dehydrogenation reactivity of hypervalent iodine(Ⅲ) reagents for carbocyclic carbonyl compounds. DFT calculations reveal that the rate-determining step is the electrophilic addition of PhI+OH onto enolate of monodehydrogenated product.

关键词： Koser’s reagent double dehydrogenation hypervalent twisting 2,3-benzotropone DFT calculations

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Chromo-chemodosimetric detection for Fe^(2+) by Fenton reagent-induced chromophore-decolorizing of halogenated phenolsulfonphthalein derivatives

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Science China Chemistry 2010年第6期53卷 1398-1405页

作者： ZHENG Kuan,LAI ChengYue,HE LiPing & LI Fang Key Laboratory of Green Chemistry and Technology,Ministry of Education College of Chemistry,Sichuan University,Chengdu 610064,China Key Laboratory of Green Chemistry and Technology Ministry of Education College of Chemistry Sichuan University Chengdu China

A commercially-available sulfonphthalein derivative was demonstrated to be a chemodosimeter for Fe2+ and its sensing behavior was further investigated by UV-vis spectroscopy in aqueous media under the optimum conditions.In the presence of chlorophenol red (CPR) and H2O2,the absorption maximum at 435 nm decreased upon addition of Fe2+,resulting in a significant color change of the CPR solution from yellow to colorless.The chemosensor system did not show significant responses to a series of other metal ions including Al3+,Zn2+,Cd2+,Hg2+,Mn2+,Co2+,Fe3+,Ni2+,Cu2+,La3+,Ce4+,Th4+,Pd2+,Pb2+,Sb3+,Cr3+,Au3+,Ag+,Nd3+,Sm3+,alkali and alkaline earth metal cations,allowing for highly selective naked-eye detection of Fe2+.Quantitative analysis was carried out kinetically for practicable the Fe2+ assay when either fixed time method or the initial rate method was applied.When the detecting time was set,the decrease of absorbance signal was linear with Fe2+ concentration in the range of 0 to 7.50 × 10-5 mol L-1 and the regression equation was ΔA = 0.00759 + 0.00593CFe with a correlation coefficient r = 0.9953.The chemodosimetric system has employed an irreversible Fenton reagent-promoted oxidation of the CPR free chromophore and the hydroxyl radicals were generated in the presence of both Fe2+ and hydrogen peroxide.The mechanistic interpretation of the signaling process was partially confirmed by the radical scavenging experiment and the FT-IR analysis of the intermediates formed at different reaction periods.

关键词： colorimetric chemosensor ferrous ion sulfonphthalein Fenton reagent

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Allyltin tribromide: A versatile reagent involved in the ring-opening of epoxides

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中国科学：化学英文版 2010年第6期53卷 1294-1301页

作者： CHEN GuoHong,WANG Xin,JIN XiaoQian,LIU LingYan,CHANG WeiXing & LI Jing State Key Laboratory and Research Institute of Elemento-organic Chemistry,Nankai University,Tianjin 300071,China State Key Laboratory and Research Institute of Elemento-organic Chemistry Nankai University Tianjin China

This paper presents a versatile reagent for epoxide cleavage.The allyltin tribromide could act as a novel and easily prepared allylation reagent and halide atom donor to convert epoxides to the corresponding homoallyl alcohols and halohydrins in high yields with excellent regioselectivities under mild reaction conditions,respectively.It could also act as a Lewis acid to catalyze the ring opening reactions of epoxides with alcohols.

关键词： versatile reagent allyltin tribromide ring opening of epoxides room temperature

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Chen's reagent: A Versatile reagent for Trifluoromethylation,Difluoromethylenation, and Difluoroalkylation in Organic Synthesis

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Chinese Journal of Chemistry 2020年第2期38卷 202-212页

作者： Qiqiang Xie Jinbo Hu Key Laboratory of Organofluorine Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences345 Ling-Ling RoadShanghai 200032China

Methyl fluorosulfonyldifluoroacetate(FSO2CF2CO2Me or MFSDA),often called"Chen's reagent",is commonly used to synthesize trifluoromethylated and difluoroalkylated compounds.This important reagent was initially developed as an efficient trifluoromethylating agent by Professor Qing-Yun Chen and co-workers at Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences in 1989.

关键词： compounds. reagent reagent

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