A trans-chelating bisphosphine possessing only planar chirality and its application to catalytic asymmetric reactions

Article abstract of DOI:10.1016/j.tetasy.2004.04.033

A new chiral bisphosphine, (S,S)-2,2″-bis[(diethylphosphino)methyl]- 1,1″-biferrocene [(S,S)-EtTRAP-H], was synthesized in seven steps in 45% overall yield from ferrocenyloxazoline derived from (S)-valinol. The new chiral phosphine has only planar chirality, and is able to form a trans-chelate metal complex. (S,S)-EtTRAP-H is an effective ligand in rhodium-catalyzed asymmetric hydrosilylation of ketones (up to 94% ee). In particular, the hydrosilylation of 2-octanone yielded (S)-2-octanol with 77% ee.