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Magnesium Bromide (magnesium + bromide)
Selected AbstractsDomino Addition/N,C Heterocyclization of Azides with Allenyl Magnesium Bromide: Rapid Synthesis of 5-Butynyl-1,2,3-triazoles.CHEMINFORM, Issue 34 2007Syed Shafi Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] ZnBr2 -Catalyzed Efficient Oxidative Homo Coupling of Aryl Magnesium Bromides.CHEMINFORM, Issue 11 2007S. Ravi Kanth Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Critical evaluation of the chemical standardization procedure for measuring gastric emptying of solidsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 13 2002P. Goethals Abstract The purpose of this study was to evaluate the baking process of yolk spiked with octanoate to measure gastric emptying rate of solids. [1- 11C]octanoate was produced by the reaction of [11C]CO2 with heptyl magnesium bromide in tetrahydrofuran (THF), followed by purification with HPLC. The decay corrected radiochemical yield ranged from 24 to 38% (5.9,9.8 GBq EOS, synthesis time: 25 min; specific radioactivity ,90 GBq ,mol,1). To check the evaporation of [1- 11C]octanoate during the baking process of yolk, [1- 11C]octanoate or potassium [1- 11C]octanoate, respectively, was added. An important fraction of the acid evaporated while for the potassium [1- 11C]octanoate <10% disappeared. Conclusion: potassium (1- 13C)octanoate is a better tracer than (1- 13C) octanoate to study gastroenterological phenomena. Copyright © 2002 John Wiley & Sons, Ltd. [source] Enantiomerically Pure Titanium Complexes Containing an [OSSO]-Type Bis(phenolate) Ligand: Synthesis, Structure, and Formation of Optically Active OligostyrenesCHEMISTRY - AN ASIAN JOURNAL, Issue 8-9 2008Geert-Jan M. Meppelder Abstract Chiral 1,2- trans -dithiocyclohexanediyl-bridged bis(phenols) of the type [2,2,-{HOC6H2 -6-R1 -4-R2}2S2C6H10] ([OSSO]H2, R1=tBu, iPr, H; R2=tBu, iPr, Me) could be conveniently and selectively synthesized in three steps, starting from cyclohexene oxide and arene thiolate. The racemic bis(phenols) could be resolved using an enantiopure (S)-camphorsulfonic ester auxiliary or by (chiral) HPLC. Complexation of the racemic bis(phenols) to TiX4 (X=Cl, OiPr) proceeds in a diastereoselective fashion to give only the ,,R,R and ,,S,S enantiomers. Racemic [Ti{(OC6H2 -6- tBu-4-Me)2S2C6H10}Cl2] reacts with benzyl magnesium bromide to afford the crystallographically characterized dibenzyl complex. The benzyl cation formed using B(C6F5)3 in C6D5Br slowly decomposes at temperatures above +10,°C. When treated with methylaluminoxane, the dichloro complexes [Ti{OSSO}Cl2] polymerize styrene with activities up to 146,kg,(mol,catalyst),1,[styrene,(mol,L,1)],1,h,1; diisopropoxy complexes [Ti{OSSO}(OiPr)2] show mere trace activity. With 1-hexene as a chain-transfer agent, activated enantiopure titanium complexes give low-molecular-weight homochiral isotactic oligostyrenes, terminated by one to five 1-hexene units with Mn values as low as 750,g,mol,1 for R=tBu and 1290,g,mol,1 for R=Me. Below Mn,5000 these oligostyrenes show optical activity. [source] | ||||||||||