Recent Advances in the Synthesis of Dihydropyridine and Their Corresponding Fused Systems via Multi-Component Hantzsch Reaction Using Catalytic Nanomaterials

1,4-Dihydropyridines (1,4-DHPs) represent a versatile class of organic compounds derived from pyridines, recognized for their extensive synthetic applications and significant medical significances. Among the various synthetic methodologies available, the Hantzsch dihydropyridine synthesis is particularly notable as it provides a reliable approach to the production of these compounds. Recent advancements have markedly improved the synthetic pathways leading to Hantzsch dihydropyridines and their derivatives. This review aims to thoroughly examine the recent progress in the synthesis of 1,4-DHPs, 1,8-dioxodecahydroacridines (AD), and polyhydroquinolines (PHQ). Emphasis is placed on novel synthetic strategies reported in recent years, specifically those that employ multicomponent reactions involving aldehydes, β-ketoesters, and ammonium salts. Furthermore, these reactions are catalyzed by various nanocatalysts, including magnetic nanoparticles, nanocomposites, metal oxides, functionalized nanoparticles, and other environmentally friendly nanobiomaterials. The application of nanocatalysts in these processes is underscored by their contributions to structural integrity and activity enhancement, indicative of a paradigm shifts towards more sustainable and efficient synthetic methodologies. This review consolidates and assesses various synthetic routes facilitated by nanocatalysts while elucidating their distinct roles in improving the efficiency and selectivity of 1,4-DHP synthesis. Hence, this review may pave the way for advancements in Hantzsch reactions by employing nanomaterial catalysts for the sustainable production of 1,4-DHP derivatives.