ABSTRACT

In this paper we will report on using a series of modifiers to enhance selectivity during 1-phenyl-1-propyne over a Pd/alumina catalyst. The modifiers, transcinnamaldehyde, trans-cinnamonitrile, 3-phenylpropionitrile, and 3phenylpropylamine, were chosen to have a functionality that potentially could adsorb more strongly than an alkene and to be unreactive under the reaction conditions. Results and Discussion The reaction profile of 1-phenyl-1-propyne over Pd/alumina is shown in Figure 1. 1Phenyl-1-propyne was hydrogenated to cis-β-methylstyrene and phenylpropane. Only trace levels of trans-β-methylstyrene were detected and further hydrogenation

of cis-β-methylstyrene to phenylpropane occurred once the majority of the 1-pheny1-propyne had reacted.