Chiral Phosphinooxazolidine Ligand Derived from Prolinol: Application to the Pd-Catalyzed Asmmetric Allylic Alkylation

Abstract

Pd-catalyzed asymmetric allylic alkylation is recognized as an useful asymmetric carbon-carbon forming process, in which racemic or achiral allylic substrates can be converted to optically active products in the presence of palladium complex of chiral ligand. 1,2 Numerous chiral ligands have been developed in order to achieve high enantioselectivity in the reaction. Phosphinooxazolines such as 1 have received considerable attention as very effective chiral P,N-bidentate ligands. 3 Recently, we developed new phosphinooxazolidine ligands 2 bearing sp 3 nitrogen donor for the asymmetric catalysis. 4 The oxazolidines obtainable by simple synthetic route seem to be potential ligands for the asymmetric catalysis. In the context of our research directed towards the development of new oxazolidine ligands, we here present phosphinooxazolidine ligands derived from optically active prolinols, together with their application to the Pd-catalyzed asymmetric allylation.