Zobrazeno 1 - 10
of 11
pro vyhledávání: '"Hayder Ali Zahalka"'
Publikováno v:
Tetrahedron Letters. 26:297-300
The alkylation of aromatic amines in the presence of inorganic bases is accelerated by a PT catalyst even if KHCO 3 is the base. ArNR θ ions seem not to be involved. A novel type of mechanism for a PTC process is proposed.
Autor:
Hayder Ali Zahalka, Yoel Sasson
Publikováno v:
Journal of Molecular Catalysis. 18:57-60
Alkaline hydrolysis of alkyl halides to ethers and alcohols under phase transfer conditions is accelerated in the presence of acetate ion as cocatalyst. This effect is attributed to the higher extraction coefficient of the acetate ion as compared to
Publikováno v:
Molecular Crystals and Liquid Crystals Incorporating Nonlinear Optics. 161:495-516
Water is shown to be an essential component in anion exchange process between metal salts and quaternary onium salts in organic solvents. Hydration of ion pairs in organic phases, on the other hand, reduces the nucleophilicity of anions in displaceme
Publikováno v:
The Journal of Organic Chemistry. 50:5088-5092
Autor:
Hayder Ali Zahalka, Yoel Sasson
Publikováno v:
J. Chem. Soc., Chem. Commun.. :1652-1654
Traces of water are shown to be essential for substitution reactons catalysed by quaternary ammonium salts; in chloride–formate exchange maximum rate is observed with 0.2% water content of the formate salt, and addition of dehydrating agents reduce
Autor:
Yoel Sasson, Hayder Ali Zahalka
Publikováno v:
ChemInform. 18
Publikováno v:
ChemInform. 20
Water is shown to be an essential component in anion exchange process between metal salts and quaternary onium salts in organic solvents. Hydration of ion pairs in organic phases, on the other hand, reduces the nucleophilicity of anions in displaceme
Publikováno v:
Chemischer Informationsdienst. 16
Publikováno v:
Chemischer Informationsdienst. 17
Autor:
Yoel Sasson, Hayder Ali Zahalka
Publikováno v:
Journal of the Chemical Society, Chemical Communications. :1581
Normal phase transfer catalysis, particularly of esterification and etherification reactions, is inhibited if free acids (e.g. phenols or carboxylic acids) are present in the system; since free acids are generated by aqueous phase hydrolysis a contro