Pd-Catalyzed Asymmetric Allylic Alkylation of Pyrazol-5-ones with Allylic Alcohols: The Role of the Chiral Phosphoric Acid in C–O Bond Cleavage and Stereocontrol

The combination of
a palladium complex with a chiral phosphoramidite
ligand and a chiral phosphoric acid enables the first highly efficient
asymmetric allylic alkylation of pyrazol-5-ones with allylic alcohols,
affording multiply functionalized heterocyclic products in high yields
with excellent enantioselectivities that would be of great potential
in the synthesis of pharmaceutically interesting molecules.