Hypervalent Iodine(III)-Catalysed Enantioselective α-Acetoxylation of Ketones

An enantioselective catalytic synthesis of alpha-acetoxylated ketones through I(I)/I(III) catalysis using a resorcinol/lactamide-based chiral iodoarene is reported. Catalyst turnover by in situ generation of the active iodine(III) derivative is achieved by oxidation with mCPBA in the presence of acetic acid. The prior transformation of ketones to easily accessible acetyl enol ethers is beneficial and yields up to 97 % with enantioselectivities up to 88 % eeare obtained using only low catalyst loadings of only 5 mol % under mild reaction conditions.