Progress in Synthesis of 1,4-Dihydropyridines

1,4-Dihydropyridines (1,4-DHPs) are an important class of heterocyclic compounds, and possess a broad array of biological activities and applications. With the development of green organic synthetic chemistry, some important achievements have been made in the green synthesis of 1,4-DHPs and new synthetic methods, which made up some shortcomings of the traditional synthesis of Hantzch reaction, such as environment friendly, synthesis efficiency, single product structure and lack of reaction type. This review provides the first overview for the green synthesis of Hantzch reaction and new synthetic methods of 1,4-DHPs since 2010. A comprehensive and up-to-date introduction are given for Hantzch reaction under geen solvent, geen catalyst and geen synthetic technology, and the new reaction of synthesis of 1,4-DBPs based on new building blocks. A thorough analysis is provided concerning the feature of improvement of green synthesis of Hantzsch reaction and new synthetic method. Moreover, the substrates, conditions, selectivities and yields have been also described. Finally, a brief discussion relating to developments and potential areas of further research concerning new synthetic methods of 1,4-DHPs and green synthesis, and chiral synthesis, is presented.