Synthesis of Chiral 1,1,1-Trifluoro--disubstituted 2,4-Diketones via Palladium-Catalyzed Asymmetric Allylation.

Trifluoromethyl ketones are important enzyme inhibitors and versatile synthons for the preparation of trifluoromethylated heterocycles and complex molecules. An efficient methodology for the synthesis of chiral 1,1,1-trifluoro-α,α-disubstituted 2,4-diketones via palladium-catalyzed allylation with allyl methyl carbonates under mild conditions has been developed. This method surmounts the major obstacle of detrifluoroacetylation, and a chiral trifluoromethyl ketone library could be rapidly built up from simple substrates in good yields and enantioselectivities, thereby offering a new choice for scientists in pharmaceutical and material industries.