Three-Component Castagnoli-Cushman Reaction of 3-Arylglutaconic Acids with Aromatic Aldehydes and Amines Delivers Rare 4,6-Diaryl-1,6-dihydropyridin-2(3 H)-ones.

Attempted use of 3-arylglutaconic acids in the three-component version of the Castagnoli-Cushman reaction with amines and aromatic aldehydes resulted in an unexpected formation of 4,6-diaryl 1,6-dihydropyridine-2(3 H)-ones. These are of interest as representatives of a rare heterocyclic chemotype for de novo biological investigation. Alternatively, these compounds can be oxidized into their 2-pyridone counterparts, stereoselectively reduced to give cis-configured 4,6-diaryl 2-piperidones, or isomerized to 5,6-dihydropyridin-2(1 H)-ones. All the three scaffolds are well represented in the bioactive compound domain.