Catalytic Enantioselective Michael Addition of 1‐Fluorobis(phenylsulfonyl)methane to α,β‐Unsaturated Ketones Catalyzed by Cinchona Alkaloids

A catalyst worth its salt: The ammonium salts of cinchona alkaloids possessing sterically demanding substituents effectively catalyzed the enantioselective 1,4-conjugate addition of 1-fluorobis(phenylsulfonyl)methane to α,β-unsaturated ketones to furnish the Michael adducts in high yield with excellent enantioselectivity (see scheme). The adducts are useful for the synthesis of chiral monofluoromethylated molecules.