Incorporation of Axial Chirality into Phosphino-Imidazoline Ligands for Enantioselective Catalysis

A complementary strategy for ligand tuning that enables controlling ligand conformation is described here. The concept is demonstrated with new ligands that are employed in the catalytic enantioselective preparation of the highly important C2-aminoalkyl five-membered heterocycle motif. The alkynylation/cyclization sequence developed here is convergent, highly modular, and allows for a complementary scope to the heteroarylation of imines. This new ligand platform should offer new possibilities for expanding the use of PHIM-type ligands in a large variety of new transformations.