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Successive Reactions (successive + reaction)
Selected AbstractsRhodium-Catalyzed Asymmetric 1,4-Addition of Alkenylsilanes Generated by Hydrosilylation of Alkynes: A One-Pot Procedure Where a Rhodium/(S)-Binap Complex Catalyzes the Two Successive Reactions.CHEMINFORM, Issue 3 2005Yusuke Otomaru Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of Optically Active Polymer with P-Stereogenic Phosphine UnitsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 19 2010Yasuhiro Morisaki Abstract Optically active polymer containing P-stereogenic bisphosphine as a repeating unit in the main was successfully synthesized. A coordinated borane on the phosphorus atom could be completely removed by an organic base under mild condition, and the successive reaction with Pd afforded the corresponding polymer complex. The chirality of P-stereogenic centers was transferred to the m-phenylene-ethynylene linkers by complexation because of the prohibition of the rotary motion of the bisphosphine-Pd unit. [source] Sharpless Asymmetric Dihydroxylation of Olefins in WaterSurfactant Media with Recycling of the Catalytic System by Membrane NanofiltrationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2008Abstract This paper presents a new and more sustainable alternative approach for the Sharpless catalytic asymmetric dihydroxylation (AD) of olefins using a water/surfactant system as reaction media. The AD reaction was performed using several cationic and anionic surfactants allowing yields and enantiomeric excesses higher or comparable with the conventional systems (using organic mixtures). The use of this water/surfactant medium offers the additional advantage of performing the reactions without the need of a slow addition of olefins. Asymmetric dihydroxylation of 1-hexene in a 1.5,mM sodium cholate aqueous solution, using N -methylmorpholine N -oxide (NMO) as co-oxidant was selected as model system to evaluate the feasibility of recycling the Sharpless catalytic system by nanofiltration. The reaction media was processed by nanofiltration, the product was isolated in the permeate, whereas the catalytic system and surfactant were retained by the membrane and recycled through six successive reactions, improving the catalyst turn-over number. The experimental results were compared with the ones calculated on the basis of mass balances, membrane rejections to product and reaction yields. [source] Relationship between inactivation kinetics of a Listeria monocytogenes suspension by chlorine and its chlorine demandJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2004R. Virto Abstract Aims:, Chlorine demand by Listeria monocytogenes cells and inactivation of L. monocytogenes by chlorine (0·6,1·0 mg l,1) at different temperatures (4, 20 and 30°C) have been investigated in a batch reactor. Methods and Results:, Chlorine demand depended on the microbial concentration and was independent on the initial chlorine concentration and temperature. Chlorine decay was modelled by the addition of two first-order decay equations. Inactivation of L. monocytogenes by chlorine depended on the initial microbial concentration, initial chlorine concentration and temperature. A mathematical model based on a biphasic inactivation properly described survival curves of L. monocytogenes and a tertiary model was developed that satisfactorily predicted the inactivation of L. monocytogenes by different concentrations of initial chlorine at different temperatures. Conclusions:, Both available chlorine decay and inactivation of L. monocytogenes by chlorine were biphasic and can be modelled by a two-term exponential model. Significance and Impact of the Study:, The biphasic nature of survival curves of L. monocytogenes did not reflect the effect of a change of available chlorine concentration during the treatment. The microbial inactivation was caused by successive reactions that occur after the consumption of the chlorine by the bacterial cell components. [source] Use of copper(II)/ethylene diamine-cotton complex for the adsorption of residual dyesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007Mohamed Hassen V. Baouab Abstract The chemical modification of cotton is performed by successive reactions with thionyl chloride followed by ethylene diamine (ED) to prepare aminoalkyl amino cotton namely ED-cotton. Evidence of attaching ethylene diamine groups onto cotton is provided by nitrogen determination and thermogravimetry analysis. Because of complexation, the ethylene diamine-grafted groups immobilizes Cu(II) ions from buffered solution at pH 6. The formation of a 1/1 complex is assessed by the adsorption limit values. The binary system [Cu(II)/ED-cotton] is then tested for the adsorption of two acid dyes (Acid Blue 25 and Calmagite) as ligands in the metal-coordinating process. The adsorption of Cu(II) onto ED-cotton and of the dyes onto Cu(II)/ED-cotton is followed spectrometrically. The observed stoichiometries of the ternary-formed complex [Dye/Cu(II)/ED-cotton] are 1/1/1 with Acid Blue 25 and 0.75/1/1 with Calmagite at 20°C. The Langmuir and Freundlich isotherms constants for the adsorption of the tested dyes onto Cu(II)/ED-cotton are evaluated from the experimental data, but better agreement is obtained by using the composite isotherm of Jossens. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1389,1396, 2007 [source] Electrospray ionization mass spectrometry study on dipeptide 4-chlorobutyl ester produced from refluxing of amino acid with phosphoryl chloride in tetrahydrofuranJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 10 2005Gui Ji Zhou Abstract Phosphoryl chloride was able to promote the formation of peptide and the ringopening of tetrahydrofuran (THF) followed by a sequence of successive reactions by simply refluxing. ESI multistage tandem mass spectrometry was applied to trace the reaction and elucidate the product structures, dipeptide 4-chlorobutyl ester. Copyright © 2005 John Wiley & Sons, Ltd. [source] | |||||||||||||