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Alkyl,Alkyl Suzuki Cross-Coupling of Unactivated Secondary Alkyl Chlorides,ANGEWANDTE CHEMIE, Issue 37 2010
Es git keine Problemsubstrate! In einer speziell für die Titelsubstrate entwickelten Reaktion gelingen C-C-Verknüpfungen mit Alkylboranen in guter Ausbeute bei Raumtemperatur mit kommerziell erhältlichen Katalysatorkomponenten (siehe Schema). Die Methode eignet sich auch für Suzuki-Reaktionen sekundärer und primärer Alkylbromide und -iodide sowie primärer Alkylchloride. [source]
Conversion of Hydrazones to Alkyl Chlorides under Swern Oxidation Conditions.CHEMINFORM, Issue 6 2007
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]
Photoinduced Electron Transfer Reactions by SmI2 in THF: Luminescence Quenching Studies and Mechanistic InvestigationsCHEMISTRY - A EUROPEAN JOURNAL, Issue 10 2005
Edamana Prasad Dr.
Abstract Photoluminescence quenching studies of SmI2 in dry THF were carried out in the presence of five different classes of compounds: ketone, alkyl chloride, nitrile, alkene and imine. The free energy change (,G,0) of the photoinduced electron transfer (PET) reactions was calculated from the redox potentials of the donor (SmI2) and acceptors. The bimolecular quenching constants (kq) derived from the Stern,Volmer experiments parallel the free energy changes of the PET processes. The observed quenching constants were compared with the theoretically derived electron transfer rate constants (ket) from Marcus theory and found to be in good agreement when a value of ,=167 kJ,mol,1 (40 kcal,mol,1) was used for the reorganization energy of the system. A careful comparison of the excited state dynamics of SmII in the solid state to the results obtained in solution (THF) provides new insight in to the excited states of SmII in THF. The activation parameters determined for the PET reactions in SmI2/1-chlorobutane system are consistent with a less ordered transition state and high degree of bond reorganization in the activated complex compared to similar ground state reactions. Irradiation studies clearly show that SmI2 acts as a better reductant in the excited state and provides an alternative pathway for rate enhancement in known and novel functional group reductions. [source]
Helical Chiral Pyridine N -Oxides: A New Family of Asymmetric CatalystsCHEMISTRY - A EUROPEAN JOURNAL, Issue 30 2009
Jinshui Chen Dr.
Abstract Optically active chiral alkyl chlorides are valuable compounds because of their bioactivity and versatile synthetic utility. Accordingly, the ring opening of epoxides with a chloride nucleophile stands as an important goal in asymmetric catalysis. We describe herein recent advances in the design and development of chiral pyridine N -oxide catalysts for the enantioselective synthesis of chlorohydrins. [source]
Gas Phase Conversion of Carbon Tetrachloride to Alkyl Chlorides Catalyzed by Supported Ionic LiquidsCHINESE JOURNAL OF CHEMISTRY, Issue 9 2009
Abstract An efficient way of converting carbon tetrachloride (CTC) to alkyl chlorides is reported, which uses the catalysts of ionic liquids supported on granular active carbon. The catalytic performance was evaluated in a temperature range of 120,200°C and atmospheric pressure for different ionic liquids, namely 1-butyl-3-methylimidazolium chloride, 1-octyl-3-methylimidazolium chloride, hydrochloric salts of N- methylimidazole (MIm), pyridine and triethylamine, as well as bisulfate and dihydric phosphate of N- methylimidazole. On this basis, the reaction mechanism was proposed, and the influences of the reaction temperature and the attributes of ionic liquids were discussed. The overall reaction was assumed to be comprised of two steps, the hydrolysis of CTC and reaction of HCl with alcohols under acidic catalyst. The results indicate that the conversion of CTC increased monotonically with temperature and even approached 100% at 200°C, while the maximum selectivity to alkyl chlorides was obtained around 160°C. This reaction might be potentially applicable to the resource utilization of superfluous byproduct of CTC in the chloromethane industry. [source]