Methyl 3-trimethylsilylpropargyl carbonate reacted with dinucleophiles under the catalysis of palladium(0) complex to give the corresponding desilylated annulation products.
With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis co...With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis constant ( K _m),maximum velocity ( v _m) and apparent maximum velocity ( v _ am ) of amylase catalyzed reaction were obtained using thermokinetic theory and reduced extent method. On the basis of data obtained,the following relationships between K _m and concentration of metal ion ( c ) were established: for inhibitor of Ni 2+ K _m=2.9648×10 -3 -1.3912×10 -4 cR =0.9998for inhibitor of Co 2+ K _m=1.0227×10 -3 +8.2676×10 -6 cR =0.9955for activator of Ca 2+ K _m=1.0630×10 -7 c 2-1.8311×10 -6 c +9.3058×10 -6 R =0.9999for activator of Li + K _m=5.6300×10 -8 c 2-1.5329×10 -6 c +1.2662×10 -5 R =0.9999 The K _m- c relationships show a strenuous inhibitory effect for Ni 2+ and a strenuous active effect for Ca 2+ .展开更多
β-Bromovinyl tellurides are new difuctional reagents which undergo palladium-catalyzed cross-coupling reaction with alkenes to give conjugated dienyl tellurides.
Propargylic carbonates reacted with dialkyl cycloalkanone-α,α′-dicarboxylates under the catalysis of Pd(0)complex to give bicyclic compounds in high yields.The two electron-withdrawing groups at α and α′position...Propargylic carbonates reacted with dialkyl cycloalkanone-α,α′-dicarboxylates under the catalysis of Pd(0)complex to give bicyclic compounds in high yields.The two electron-withdrawing groups at α and α′positions of cycloalkanone rings are essential for the annulation reaction.展开更多
9-Chlorofluorene reacted with aromatic aldehydes and ketones in the presence of phase transfer catalyst, giving the Darzens condensation epoxy products.
The yield and stereoselectivity of the Diels-Alder reactions between furan(or 2-methylfuran)and different dienophiles are markedly enhanced by the catalysis of anhydrous YbCl_3.
The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to ...The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to epoxy group and 0. 74 order with respect to dimethylbenzylamine. The reaction rate constants at various temperatures and activation energy were determined. The mechanism of this reaction was discussed. Keywords Tetrabromobisphenol-A, Bromo-epoxy resin, Oleic acid kinetics, Reaction mechanism展开更多
In this paper,we report a full account of the synthesis of dimeric hexahydropyrroloindole alkaloids and its analogues.The key feature of our new strategy is the novel catalytic copper(10%)mediated intramolecular aryla...In this paper,we report a full account of the synthesis of dimeric hexahydropyrroloindole alkaloids and its analogues.The key feature of our new strategy is the novel catalytic copper(10%)mediated intramolecular arylations of o-haloanilides followed by intermolecular oxidative dimerization of the resulting oxindoles in one pot.This sequential reaction leads to the key intermediates for the synthesis of(+)-chimonanthine,(+)-folicanthine,(-)-calycanthine and(-)-ditryptophenaline.Graphical Abstract In the presence of catalytic amount of cuprous iodide(10%),an intramolecular arylation of ohaloanilides followed by an intermolecular oxidative dimerization of the resulting oxindoles leads to a commonintermediate for the synthesis of(+)-chimonanthine,(+)-folicanthine and(-)-calycanthine.Based on this cascade sequence,we also developed a flexible strategy towards the asymmetric syntheses of dimeric HPI alkaloids(-)-ditryptophenaline and its analogues.展开更多
The potentially bioactive 2-aryl-thiazolo[4,5-b]pyridines were synthesized via palladium-catalyzed desulfitative cross-coupling reaction between multisubstituted thiazolo[4,5-b]pyridine thioethers and boronic acids. Y...The potentially bioactive 2-aryl-thiazolo[4,5-b]pyridines were synthesized via palladium-catalyzed desulfitative cross-coupling reaction between multisubstituted thiazolo[4,5-b]pyridine thioethers and boronic acids. Yields of 48%–94% were obtained with copper（I） thiophene-2-carboxylate in the system.展开更多
Novel fluorescent coumarin-4H-pyran conjugates were achieved by three-component reactions of various synthetic β-ketoesters with aldehydes and malononitrile in aqueous media.Besides mild reaction conditions,operation...Novel fluorescent coumarin-4H-pyran conjugates were achieved by three-component reactions of various synthetic β-ketoesters with aldehydes and malononitrile in aqueous media.Besides mild reaction conditions,operational simplicity,absence of tedious separation procedures,using of inexpensive and nontoxic commercially available cationic surfactant cetyltrimethylammonium chloride（CTAC） as a catalyst are the prominent advantage of this method.展开更多
Achieving efficient integration of cancer diagnosis and therapy is of great significance to human health,but the construction of a multifunctional intelligent therapy system still faces great challenges.In this study,...Achieving efficient integration of cancer diagnosis and therapy is of great significance to human health,but the construction of a multifunctional intelligent therapy system still faces great challenges.In this study,we report an integrated multifunctional nanocomposite constructed by a simple modular assembly technology.The nanocomposites are composed of three different nanomaterials:Fe_(3)O_(4),Au,and NaErF_(4):0.5%Tm@NaYF_(4)upconversion nanoparticles(UCNPs).In this design,Fe_(3)O_(4)nanoparticles have nanozyme effect of peroxidase-like activity,which can react with H_(2)O_(2)in the tumor microenvironment to generate hydroxyl radicals.Because of its magnetic properties,it can help the nanocomposites to aggregate under the induction of magnetic fields.Au nanoparticles exhibit nanozyme effect of glucose oxidase-like activity.It can catalyze the conversion of glucose to gluconic acid and H_(2)O_(2).Ingeniously,the generated H_(2)O_(2)provides a source of reactants for the reaction of the Fe_(3)O_(4)nanozyme.In addition,the photothermal effect of Au nanoparticles under 808 nm irradiation further enhanced the nanozyme activity of Fe_(3)O_(4)and Au nanoparticles.Besides,UCNPs can emit near-infrared(NIR)-II fluorescence under 808 nm irradiation,which can provide imaging-guided during cancer treatment.Then,the nanocomposites were further modified by poly(vinylpyrrolidone)(PVP)to obtain UCNPs/Au/Fe_(3)O_(4)-PVP with good biocompatibility and high-efficiency cancer treatment ability.展开更多
文摘Methyl 3-trimethylsilylpropargyl carbonate reacted with dinucleophiles under the catalysis of palladium(0) complex to give the corresponding desilylated annulation products.
基金ProjectsupportedbytheNaturalScienceFoundationofShandongProvince (No .Y2 0 0 0B0 3 )
文摘With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis constant ( K _m),maximum velocity ( v _m) and apparent maximum velocity ( v _ am ) of amylase catalyzed reaction were obtained using thermokinetic theory and reduced extent method. On the basis of data obtained,the following relationships between K _m and concentration of metal ion ( c ) were established: for inhibitor of Ni 2+ K _m=2.9648×10 -3 -1.3912×10 -4 cR =0.9998for inhibitor of Co 2+ K _m=1.0227×10 -3 +8.2676×10 -6 cR =0.9955for activator of Ca 2+ K _m=1.0630×10 -7 c 2-1.8311×10 -6 c +9.3058×10 -6 R =0.9999for activator of Li + K _m=5.6300×10 -8 c 2-1.5329×10 -6 c +1.2662×10 -5 R =0.9999 The K _m- c relationships show a strenuous inhibitory effect for Ni 2+ and a strenuous active effect for Ca 2+ .
基金This work was supported by Natural Science Foundation of Zhejiang Province.
文摘β-Bromovinyl tellurides are new difuctional reagents which undergo palladium-catalyzed cross-coupling reaction with alkenes to give conjugated dienyl tellurides.
基金Work supported by the National Natural Science Foundation of China and Chinese Academy of Sciences
文摘Propargylic carbonates reacted with dialkyl cycloalkanone-α,α′-dicarboxylates under the catalysis of Pd(0)complex to give bicyclic compounds in high yields.The two electron-withdrawing groups at α and α′positions of cycloalkanone rings are essential for the annulation reaction.
文摘9-Chlorofluorene reacted with aromatic aldehydes and ketones in the presence of phase transfer catalyst, giving the Darzens condensation epoxy products.
文摘The yield and stereoselectivity of the Diels-Alder reactions between furan(or 2-methylfuran)and different dienophiles are markedly enhanced by the catalysis of anhydrous YbCl_3.
文摘The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to epoxy group and 0. 74 order with respect to dimethylbenzylamine. The reaction rate constants at various temperatures and activation energy were determined. The mechanism of this reaction was discussed. Keywords Tetrabromobisphenol-A, Bromo-epoxy resin, Oleic acid kinetics, Reaction mechanism
基金This work was supported by Grants from Natural Science Foundation of China(20925205 and 21332007)the Program for Changjiang Scholars and Innovative Research Team in University(IRT13095)+1 种基金Yunnan Provincial Science and Technology Department(2010GA014)the Program for Yunling Scholars.Dr.Xiaonian Li of the Kunming Institute of Botany is gratefully acknowledged for X-ray crystallographic analysis of compound 23.CCDC 1409209(23).
文摘In this paper,we report a full account of the synthesis of dimeric hexahydropyrroloindole alkaloids and its analogues.The key feature of our new strategy is the novel catalytic copper(10%)mediated intramolecular arylations of o-haloanilides followed by intermolecular oxidative dimerization of the resulting oxindoles in one pot.This sequential reaction leads to the key intermediates for the synthesis of(+)-chimonanthine,(+)-folicanthine,(-)-calycanthine and(-)-ditryptophenaline.Graphical Abstract In the presence of catalytic amount of cuprous iodide(10%),an intramolecular arylation of ohaloanilides followed by an intermolecular oxidative dimerization of the resulting oxindoles leads to a commonintermediate for the synthesis of(+)-chimonanthine,(+)-folicanthine and(-)-calycanthine.Based on this cascade sequence,we also developed a flexible strategy towards the asymmetric syntheses of dimeric HPI alkaloids(-)-ditryptophenaline and its analogues.
基金supported by the National Natural Science Foundation of China(No.21272009)
文摘The potentially bioactive 2-aryl-thiazolo[4,5-b]pyridines were synthesized via palladium-catalyzed desulfitative cross-coupling reaction between multisubstituted thiazolo[4,5-b]pyridine thioethers and boronic acids. Yields of 48%–94% were obtained with copper（I） thiophene-2-carboxylate in the system.
基金the financial support from the National Natural Science Foundation of China(No.21462041)Natural-Science Foundation for Distinguished Young Scholars of Xinjiang Uyghur Autonomous Region(No.Qn2015jq002)the Tianshan Talent Cultivation Project of Xinjiang Uyghur Autonomous Region
文摘Novel fluorescent coumarin-4H-pyran conjugates were achieved by three-component reactions of various synthetic β-ketoesters with aldehydes and malononitrile in aqueous media.Besides mild reaction conditions,operational simplicity,absence of tedious separation procedures,using of inexpensive and nontoxic commercially available cationic surfactant cetyltrimethylammonium chloride（CTAC） as a catalyst are the prominent advantage of this method.
基金This work was supported by the financial aid from the National Natural Science Foundation of China(Nos.22020102003,21834007,and 52103276)the National Key R&D Program of China(No.2020YFA0712102)+2 种基金the Program of Science and Technology Development Plan of Jilin Province of China(No.20220508076RC)the Natural Science Foundation of Guangdong Province of China(No.2022A1515010947)Guangzhou Basic and Applied Basic Research Foundation(No.202201011343).
文摘Achieving efficient integration of cancer diagnosis and therapy is of great significance to human health,but the construction of a multifunctional intelligent therapy system still faces great challenges.In this study,we report an integrated multifunctional nanocomposite constructed by a simple modular assembly technology.The nanocomposites are composed of three different nanomaterials:Fe_(3)O_(4),Au,and NaErF_(4):0.5%Tm@NaYF_(4)upconversion nanoparticles(UCNPs).In this design,Fe_(3)O_(4)nanoparticles have nanozyme effect of peroxidase-like activity,which can react with H_(2)O_(2)in the tumor microenvironment to generate hydroxyl radicals.Because of its magnetic properties,it can help the nanocomposites to aggregate under the induction of magnetic fields.Au nanoparticles exhibit nanozyme effect of glucose oxidase-like activity.It can catalyze the conversion of glucose to gluconic acid and H_(2)O_(2).Ingeniously,the generated H_(2)O_(2)provides a source of reactants for the reaction of the Fe_(3)O_(4)nanozyme.In addition,the photothermal effect of Au nanoparticles under 808 nm irradiation further enhanced the nanozyme activity of Fe_(3)O_(4)and Au nanoparticles.Besides,UCNPs can emit near-infrared(NIR)-II fluorescence under 808 nm irradiation,which can provide imaging-guided during cancer treatment.Then,the nanocomposites were further modified by poly(vinylpyrrolidone)(PVP)to obtain UCNPs/Au/Fe_(3)O_(4)-PVP with good biocompatibility and high-efficiency cancer treatment ability.
