An effective and recyclable catalyst for hydrogenation of alpha,beta-unsaturated aldehydes into saturated aldehydes in supercritical carbon dioxide

摘要

A carbon supported palladium catalyst (Pd/C) is successfully used in selective hydrogenation of alpha,beta-unsaturated aldehydes in scCO_2 and under solventless reaction conditions.The reactions take place very rapidly in scCO_2 and the average turnover frequency values for cinnamaldehyde and crotonaldehyde at 100% conversion maximally reached 3.1 and 11.6 s~(-),respectively.The catalyst can be recycled several times without loss of activity and selectivity.The products (liquid),solvent (scCO_2) and catalysts (solid) can be easily separated by a simple phase separation process.The present reaction is an ideal green chemical process in the view of industrial applications.