Enantioselective Deprotonation of 4-tert-Butylcyclohexanone by Fluorine-Containing Chiral Lithium Amides Derived from α-Phenethylamine

An α-phenethylamine-derived chiral lithium amide ( (R) - 5c ) possessing a 2,2,2-trifluoroethyl group on the amide nitrogen was found to induce high enantioselectivity in the kinetic deprotonation of 4- tert -butylcyclohexanone ( 1 ) in the presence of excess trimethylsilyl chloride to give the corresponding silyl enol ether ( (S) - 2 ) in up to 92% ee (86% chemical yield). © 1997 Elsevier Science Ltd.