Synthesis of a trans-chelating chiral diphosphine ligand with only planar chirality and its application to asymmetric hydrosilylation of ketones

Article abstract of DOI:10.1016/S0040-4039(98)02603-3

Optically active diphosphine (S,S)-2,2_-bis[(diethylphosphino)methyl]- 1,1_-biferrocene (abbreviated to (S,S)-EtTRAP-H) was synthesized from ferrocenyloxazoline derived from-L-valinol in 47% overall yield. The new chiral ligand, (S,S)-EtTRAP-H, which coordinates to a rhodium atom in a trans-chelating manner, was effective for asymmetric hydrosilylation of ketones to give optically active secondary alcohols with up to 94% ee.