Versatile precursor to ruthenium-bis(phosphine) hydrogenation catalysts

The known complex trans-RuCl2(NBD)Py-2 (1, NBD is norbornadiene, Py is pyri dine) reacts with either (R)-BINAP ((R)-2,2'-bis (diphenylphosphino)-1,1'-b inaphthyl), (S;S)-Chiraphos ((2S;3S-(-)-2,3-bis (diphenylphosphino)butane), (S;S)Skewphos ((2S;4S)-(-)-2,4-bis(diphenylphosphino), (R)-(S)-Josiphos (( R)-(-)-1-[ (S)-2-(diphenylphosphino)ferrocenyl]ethyl-dicyclohexylphosphine) , (R;R)-Norphos ((2R;3R)-(-)-2,3-bis(diphenylphosphino)bicyclo [2.2.1]hept- 5-ene), or (R;R)-Me-DUPHOS ((-)-1,2-bis((2R;5R)-2,5-dimethylphospholano to generate in high yields the crystalline complexes trans-RuCl2(P-P*)Py-2 (P- P* is the corresponding chiral his (phosphine)). The complexes trans-RuCl2( P-P*)Py-2 are active enantioselective hydrogenation catalysts for ketoester s and noncarboxylic olefins in the presence of small amounts of HBF4 (aq.). They are active for hydrogenation of carboxylic substrates in the presence of Et3N. Reaction of trans-RuCl2(P-P*)Py-2 with (rac)-1,2-diphenylethylene -diamine (N-N*, either enantiomer) forms in good yields the corresponding c ompounds trans-RuCl2(P-P*) (N-N*). Representative hydrogenations with these catalysts are presented. (C) 2000 Wiley-Liss, Inc.