Palladium Complexes of Chiral Planar 1-Phosphino-2-sulfenylferrocenes as Efficient Catalysts in Enantioselective Diels-Alder Reactions

The readily available dichloride palladium complexes of chiral planar (R)-1-phosphino-2-sulfenylferrocenes (Fesulphos ligands) act as efficient Lewis acids in the catalytic asymmetric Diels−Alder reaction of cyclopentadiene with acryloyl-1,3-oxazolidin-2-one. Very high enantioselectivities, up to 95% ee, have been reached from Fesulphos ligands having a very bulky substitution at both sulfur and phosphorus coordinating atoms.