Enantioselective hydrogenation of arecaidine over cinchona alkaloid-modified palladium catalyst: A novel route to enantioenriched nipecotic acid derivatives

The hydrogenation of N-methyl-3,4-dehydronipecotic acid (arecaidine) over Pd/Al2O3 catalyst in presence of cinchona alkaloids and benzylamine additive results in the quantitative formation of N-methylnipecotic acid in good (up to 60%) optical purity. The reaction is a novel example of the efficient use of chirally modified heterogeneous metal catalysts allowing the preparation of enantioenriched N-heterocyclic carboxylic acids.