The Evolution of Phosphite-Oxazoline Ligands for the Pd-Allylic Substitution and Their Application in Building Chiral Molecules

Pd-catalyzed asymmetric allylic substitution (AAS) is a highly effective method for producing chiral molecules with alkene-substituted frameworks which can be further derivatized. However, its stereochemical outcome is affected by the steric requirements of the substrate and only a narrow set of nucleophiles yield excellent enantioselectivities. In this regard, phosphite-oxazolines have emerged as strong candidates to be privileged ligands for this process, providing results that surpass most of the previously published studies. They have provided high enantiocontrol when used in the Pd-AAS of several hindered and unhindered substrates, using a wide range of C-, O-, and N-nucleophiles. In this concept, we review and discuss the current progress made in the design of tailor-made phosphite-oxazoline ligand libraries for the Pd-AAS of a broad range of substrates and nucleophiles and its application in the construction of chiral complex molecules.