A novel synthesis of fluorine-containing quaternary amino acid derivatives via palladium-catalyzed allylation reaction

The palladium-catalyzed allylation reaction of trifluoroalanine derivatives with various allyl carbonates was examined. When N-Cbz-protected alanine derivative was employed, the desired C-monoallylated product was obtained in good yield, together with C,N-diallylated and N-monoallylated ones. Changing the protecting group from Cbz to PMP group caused an exclusive formation of C-monoallylated products in high yields. The reaction with various types of allyl carbonates also proceeded smoothly. Based on the present palladium-catalyzed allylation reaction, the total synthesis of α-CF3 leucine analogue was achieved.