A new strategy for the asymmetric allylic alkylation of azlactones with α-(trifluoromethyl)allyl
acetates catalyzed by Pd(OAc)2/(R)-BINAP is designed and developed, providing access to unsaturated α-quaternary α-amino
acid derivatives bearing a trifluoromethyl group and contiguous quaternary and tertiary
stereogenic centers. The products are obtained in good yields with exclusive regioselectivity
and excellent stereoselective control under relatively mild reaction conditions. A
scale-up experiment shows no loss of reactivity or stereoselectivity. The synthetic
utility of the current strategy is demonstrated through transformations of a representative
product to afford several potentially bioactive species.
Key words
palladium catalysis - trifluoromethyl alkylation - asymmetric catalysis - azlactones
- α-(trifluoromethyl)allyl acetates