Asymmetric hydrogenation of olefins on chiral cobalt catalytic systems

1. The Co(acac)2-PPh2(neomenthyl)-AlEt3 and Co(acac2-PPh2(O-menthyl)-AlEt3 systems are catalysts for the hydrogenation of styrene, 2-phenylbutenes, andα-ethoxystyrene and give low optical yields. 2. A possible mechanism is proposed for the hydrogenation and enantioselectivity of the catalyst action.