Nitrophenylacetonitriles as Versatile Nucleophiles in Enantioselective Organocatalytic Conjugate Additions

Arylacetonitriles are able to participate in organocatalytic Michael additions to alpha,beta-unsaturated aldehydes by incorporating a nitro group at the phenyl ring, which acts as a temporary activating group in a remote position and allows further transformations. The sequential protocol Michael addition/NaBH4 reduction/lactonization allows the synthesis of diastereomerically pure disubstituted lactones in high yield and optical purity.