Iridium-Catalyzed Enantioselective Fluorination of Racemic, Secondary Allylic Trichloroacetimidates

The
Ir-catalyzed enantioselective fluorination of racemic, branched
allylic trichloroacetimidates with Et3N·3HF is a mild
and efficient route for selective incorporation of fluoride ion into
allylic systems. We herein describe the asymmetric fluorination of
racemic, secondary allylic electrophiles with Et3N·3HF
using a chiral-diene-ligated Ir complex. The methodology enables the
formation of acyclic fluorine-containing compounds in good yields
with excellent levels of asymmetric induction and overcomes the limitations
previously associated with the enantioselective construction of secondary
allylic fluorides bearing α-linear substituents.