Highly Enantioselective Addition of 1-Fluoro-1-nitro(phenylsulfonyl)methane to α,β-Unsaturated Aldehydes

An organocatalytic, highly enantioselective addition of 1‐fluoro‐1‐nitro(phenylsulfonyl)methane to α,β‐unsaturated aldehydes is reported. The reaction is simply catalyzed by secondary amines and furnishes the corresponding fluorinated derivatives in good yields, with moderate diastereoselectivities and excellent enantioselectivities. The absolute configuration of the major diastereomers was unambiguously ascertained by X‐ray diffraction analysis. An asymmetric organocatalytic Michael addition of 1‐fluoro‐1‐nitro(phenylsulfonyl)methane to aromatic or aliphatic α,β‐unsaturated aldehydes is reported. The reaction is efficiently catalyzed by commerciallyavailable chiral pyrrolidine derivatives and gives the corresponding adducts in moderate to good yields, with moderate diastereoselectivities and excellent enantioselectivities (up to 99:1 er).