A Flexible Approach to Different Families of Bidentate P,P Ligands as Highly Efficient Ligands for Asymmetric Catalysis



A novel and versatile approach has led to the synthesis of various classes of mono- and bidentate phospholane and phosphinite ligands based on a benzothiophene scaffold. The ligand functions in the bidentate ligands can be introduced independently and consecutively. A bis-phospolane ligand as well as its rhodium complex have been characterized by crystal-structure determinations. The bis-phospholane ligands were tested in the catalysed asymmetric homogeneous hydrogenation of dehydroamino acid derivatives, enamides and itaconates and gave ee values of up to 98.7 %. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)