Chiral oxazoline-1,3-dithianes: new effective nitrogen–sulfur donating ligands in asymmetric catalysis

A series of new chiral oxazoline-1,3-dithianes has been easily synthesized and used as ligands for asymmetric catalysis. The conjugate addition of Et2Zn to enones resulted in ees of up to 69%, whereas the Pd-catalyzed allylic alkylation led to the expected products in almost quantitative yields and up to 90% enantioselectivity. The ligand's conformation has been explored using a combination of X-ray and NMR measurements, indicating the presence of a remarkable anomeric effect, which accounts for the preference of the oxazoline ring for the axial location.