Ag+-Assisted Hydrosilylation:  Complementary Behavior of Rh and Ir Catalysts (Reversal of Enantioselectivity)

2007-03-29T00:00:00Z (GMT) by Anders Frölander Christina Moberg
The presence of a suitably situated hydroxy function in a PHOX ligand leads to an enhancement of the enantioselectivity in Rh-catalyzed hydrosilylations of prochiral ketones in the presence of AgBF4 (95% ee for acetophenone as compared to 75% using i-Pr−phosphinooxazoline (PHOX)). Exchanging Rh for Ir affords the product with the opposite absolute configuration (78% ee).