Recent studies on asymmetric hydrogenation. New catalysts and synthetic applications in organic synthesis

Abstract

CODRu(η3methylallyl)2 is a versatile starting material for the preparation of a wide range of chiral bisphosphines ruthenium(II) complexes: (P*P)Ru(η3methylallyl)2 2, Ru[X4(P*P)2] 3, and cationic monohydride ruthenium complex 4. A facile synthesis of new C2 electron-rich chiral phosphines, bis(phosphetano)benzene 8 and 1,1'bis(phosphetano)ferrocene 10 is presented. Dynamic kinetic resolution was used for efficient syntheses of key components of the hexahydroazepane core 16 of balanol and of optically pure Boc(2S,3R,3S)-iso-dolaproïne 19. Catalyst 4 was used in asymmetric hydrogenation of 22 to give (+)-cis-methyl dihydrojasmonate in high enantioselectivity.