Journal of Molecular Catalysis A-Chemical, Vol.241, No.1-2, 101-110, 2005
Synthesis and characterization of novel multi-site phase transfer catalyst and its catalytic efficiency for dichlorocarbene addition to citral
Novel soluble multi-site phase transfer catalyst was synthesized from low cost starting materials and its catalytic efficiency is assessed by observing the kinetics of dichlorocarbene addition to citral in the absence of solvents. This new synthesized phase transfer catalyst viz., 1,3,5-tris[4-{2,3-bis(triethylammoniummethylene chloride)}-phenoxymethyl]benzene possesses six active centers. This novel catalyst has higher activity than the commercially available single-site phase transfer catalysts. The dichlorocarbene addition to citral reaction was carried out at low temperature (40 degrees C) under pseudo-first order conditions by keeping low concentration of aqueous sodium hydroxide and excess of chloroform and the disappearance of citral were monitored by gas chromatography. The effect of various experimental parameters such as [substrate], [catalyst], [aqueous NaOH], stirring speed and temperature on the rate of the reaction has been studied, and based on the kinetic results obtained, a plausible mechanism is proposed. (c) 2005 Elsevier B.V. All rights reserved.
Keywords:phase transfer catalyst;dichlorocarbene;citral;multi-site;interfacial mechanism;dihalocyclopropane