A green one-pot three-component cascade reaction: the synthesis of 2-amino-5,8-dihydro-3H-pyrido[2,3-D]pyrimidin-4-ones in aqueous medium

Construction of 1,4-Dihydropyridines: The Evolution of C4 Source

The field of cascade cyclization for the construction of 1,4-dihydropyridines (1,4-DHPs) has been continuously expanding during the last decades because of their broad-spectrum biological and synthetic importance. To date, many methods have been developed, mainly including the Hantzsch reaction, Hantzsch-like reaction and newly developed cascade cyclization, in which various synthons have been successively developed as C4 sources of 1,4-DHPs. This review presents the cascade cyclization synthesis strategy for the construction of 1,4-DHPs according to various C4 sources from carbonyl compounds, alkenyl fragments, alcohols, aliphatic amines, glycines and other C4 sources.

Recent Developments in the Synthesis of Bicyclic Condensed Pyrimidinones

Abstract:

Functionalized bicyclic pyrimidinones and their derivatives are significant heterocyclic scaffolds being their all-around prevalence in biologically potent compounds. In several attempts to explore the different synthetic methodologies for the construction of bicyclic condensed pyrimidinones, different researchers from all across the globe have reported numerous substantial methods. In the present review, considerable work has been critically compiled on the synthesis of substituted and functionalized bicyclic pyrimidinones from 2000 onwards.

Diversity-oriented catalyst-free synthesis of pseudopeptides containing rhodanine scaffolds via a one-pot sequential isocyanide-based six-component reactions in water using ultrasound irradiation

A planning strategy for diversity-oriented catalyst-free synthesis of pseudopeptides containing rhodanine scaffolds has been developed via a novel one-pot sequential six-component reaction in water. This approach is an efficient, environmentally friendly and expeditious procedure for direct access to wide ranges of pharmacologically significant and structurally interesting compounds based on the union of multicomponent reactions approach via tandem Michael/domino cycloaddition/Ugi reactions sequence from readily available starting materials. The syntheses were achieved by reaction of various primary amines, carbon disulfide, maleic anhydride or itaconic anhydride, aromatic aldehydes, anilines and isocyanides under ultrasound irradiation at room temperature in good yields. Providing of pseudopeptides containing rhodanines with the tandem formation of one new heterocyclic ring as well as creating the seven new bonds such as carbon-carbon, carbon-nitrogen, carbon-oxygen and carbon-sulfur with great efficiency and high atom/bond-forming/structure economy are outstanding features of this designed synthetic route.