Fluorous chiral bisoxazolines. Synthesis and applications to an asymmetric allylic alkylation

The easily accessible fluorous bisoxazolines 3a–b bearing two fluorous ponytails are efficient ligands in the palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenylprop-2-enyl acetate with carbonucleophiles in benzotrifluoride or CH2Cl2, enantioselectivities of up to 95% being obtained. The ligand is easily separated from the reaction mixture by simple extraction with a fluorous solvent.