Cobalt-Catalyzed Asymmetric Allylation of Cyclic Ketimines.

A CoII /Box-catalyzed [Box=bis(oxazoline)] enantioselective addition of potassium allyltrifluoroborate to cyclic ketimines was developed, providing the corresponding chiral α-tertiary amines in high yields and with good enantioselectivity values. Alkoxycarbonyl- and alkyl-substituted saccharin-derived ketimines are suitable substrates for this allylation reaction. The product can be converted to complex molecules over several simple steps, including a precursor of MK-0371, which is a kinesin spindle protein inhibitor. In addition, this catalytic system showed a strong positive nonlinear effect.