The Solvent-less Hydrogenation of Unsaturated Esters using 0.5%Pd/Al(O)OH as a Catalyst

Catalytic hydrogenation is a common method used for the conversion of alkenes to alkanes. Typically these reactions are conducted in solution using a homogeneous or heterogeneous transition metal catalyst and a source of H2. With the growing interest in green chemistry, it is desirable to provide students with the opportunity to conduct a green hydrogenation experiment. In this experiment, students use a 0.5%Pd/Al(O)OH catalyst to hydrogenate an alkene in the absence of solvent. This catalyst can be recovered without a loss in activity. The yield is virtually quantitative and the reaction is complete within 50 minutes at room temperature. This reaction exemplifies many of the principles of green chemistry and should be a nice addition to the experiments that undergraduates conduct in an organic chemistry lab (Scheme 1).