Enantioselective Synthesis of Chromanones Bearing an α,α-Disubstituted α-Amino Acid Moiety via Decarboxylative Michael Reaction

Pyridylacetic acids and related systems as alkylheteroarene surrogates in asymmetric decarboxylative Michael addition

In this manuscript, a novel method for the preparation of enantiomerically enriched pyridine derivatives has been described. It is based on the utilization of readily available 2-pyridylacetic acids as valuable synthons for the introduction of a pyridine ring in an asymmetric fashion. They have been used as pronucleophiles in asymmetric decarboxylative Michael addition to α,β-unsaturated aldehydes. The synthesis based on iminium activation using a chiral aminocatalyst that controlled the stereochemical outcome of the transformation has been successfully accomplished.