Heterogeneous Enantioselective Hydrogenation of Aromatic Ketones Catalyzed by Cinchona-and Phosphine-Modified Iridium Catalysts

摘要

Heterogeneous catalytic systems for asymmetric reactions are fascinating because of their potential in synthetic applications.'11 However,because of the high substrate specificity of these catalysts,the complexity of the task at hand,and the difficulties in understanding and designing the catalytic reactions,there have been just three established systems reported.One system identified for asymmetric hydrogenation is the cinchona-modified Pt/Al2O3 for asymmetric hydrogenation of alpha-keto esters,which was developed by Orito et al.in 1979.Baiker et al.successfully us6d this catalyst in the asymmetric hydrogenation of activated aromatic ketones.However,when considering the asymmetric hydrogenation of simple aromatic ketones and derivatives,which are among the most fundamental subjects in modern synthetic chemistry,few successful heterogeneous catalytic examples are reported.