Economic preparation of 1,3-diphenyl-1,3-bis(diphenylphosphino)propane: a versatile chiral diphosphine ligand for enantioselective hydrogenations

✍ Scribed by Natalia V. Dubrovina; Vitali I. Tararov; Axel Monsees; Renat Kadyrov; Christine Fischer; Armin Börner

• Book ID: 104360055
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 198 KB
• Volume: 14
• Category: Article
• ISSN: 0957-4166
• DOI: 10.1016/s0957-4166(03)00595-0

✦ Synopsis

The enantioselective hydrogenation of 1,3-diarylpropane-1,3-diones with chiral Ru(II)-diphosphine catalyst has been studied. In a first approach it was found, that Tol-BINAP together with Ru(COD)methallyl 2 formed the most selective catalyst. One of the C 2 -symmetric enantiopure 1,3-diols obtained in turn was transformed via its 1,3-di-O-mesylate into 1,3-bisdiarylphosphines. One of them, 1,3-diphenyl-1,3-bis(diphenylphosphino)propane, could be advantageously utilized as a ligand for the efficient enantioselective Ru-catalyzed hydrogenation of its own 1,3-diketone precursor. Thus, the condition for a 'cross self-breeding' catalytic system is fulfilled. A further reduction of the preparation costs could be achived by application of RuCl 3 •H 2 O instead of other more expensive precatalyst precursors without compromosing the enantioselectivity. The ligand was used in the Rh(I)-catalyzed asymmetric hydrogenation of model substrates and b-amino acid precursors where up to 97% ee could be achieved.