Chapter Six - Dihydropyridine Preparation and Application in the Synthesis of Pyridine Derivatives

Abstract

Abstract The preparation and application of dihydropyridines continue to attract considerable interest in organic synthesis and medicinal chemistry. The biological activities and synthetic utility of these heterocycles have prompted the development of new routes to their construction. The Hantzsch synthesis of dihydropyridines and pyridines has been well-studied and is now a very reliable method for preparing numerous symmetrical and asymmetrical derivatives. A widely used method to prepare 1,2- and 1,4-dihydropyridines involves the addition of nucleophiles to N -activated pyridines. The regioselectivity of this reaction has been shown to be dependent upon the pyridine-activating reagent and the nucleophile. Numerous catalytic methods for the construction of dihydropyridines have been developed. This review covers recent contributions to the preparation of dihydropyridines and pyridines via acyclic and cyclic precursors, the conversion of dihydropyridine intermediates to pyridines, and the synthetic utility of dihydropyridines as synthetic intermediates in organic synthesis.