One-pot chemo-biocatalytic synthesis of R-1-phenylethyl acetate from acetophenone hydrogenation over Pd/Al2O3 catalyst

Selective hydrogenation of ethyl-benzoylacetate to 3-hydroxy-3-phenyl-propionate catalyzed by Pd/C in EtOH as a solvent in the presence of KOH: The role of the enolate ion on the reaction mechanism

“…3) shows a linear trend in the range 303-333 K, the apparent activation energy of 53 kJ mol À1 calculated agrees to that found in literature for catalytic hydrogenations of several carbonyl compounds [7][8][9][10][11][12][13][14][15][16][17]. In addition, temperature has a little influence on the selectivity to HPEP, which is higher than 99% even at 333 K.…”

“…This method has been widely used to investigate the influence of the reaction conditions on the initial rates [6,8,15,18,31]. Many authors, however, criticized kinetic model assessment by using the initial reaction rate method, suggesting more reliable results by integration of the complete concentration profile [11].…”

“…Among the several metals active in ketones hydrogenation Pt, Pd and Rh are the most effective. The selectivity of the catalyst is related to the type of the metal and to the support [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Pd catalysts, under mild conditions, present the advantage that ring hydrogenations are completely avoided [4][5][6][7][12][13][14][15].…”

“…It occurs with formation of a H-C-OH moiety which may undergo further hydrogenation by the C-OH bond splitting. The selectivity of different metals towards this functional group has attracted much interest [3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”

“…The selectivity of the catalyst is related to the type of the metal and to the support [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Pd catalysts, under mild conditions, present the advantage that ring hydrogenations are completely avoided [4][5][6][7][12][13][14][15]. In addition, employing alkaline solution of ethanol in the presence of Pd/C catalysts the C-OH hydrogenolysis is practically suppressed [7,12,13] with selectivity comparable or higher than that of the Cu-based catalysts, which are highly selective but much less active [16,17].…”