Selective Reduction of Nitroarenesby a Hantzsch 1,4-Dihydropyridine: A Facile and EfficientApproach to Substituted Quinolines

An efficient reductive cyclization of o-nitrocinnamoyl compounds was achieved by employing a Hantzsch 1,4-dihydropyridine ester as a biomimetic reducing agent in the presence of catalytic palladium on carbon. This approach was successfully applied to the synthesis of substituted quinolines.