Trifluoromethyl-β-dicarbonyls as Versatile Synthons in Synthesis of Heterocycles

Trifluoromethyl group relishes a privileged position in the realm of medicinal chemistry because its incorporation into organic molecules often enhances the bioactivity by altering pharmacological profile of molecule. Trifluoromethyl-β-dicarbonyls have emerged as pivotal building blocks in synthetic organic chemistry due to their facile accessibility, stability and remarkable versatility. Owing to presence of nucleophilic and electrophilic sites, they offer multifunctional sites for the reaction. This review covers a meticulous exploration of their multifaceted role, encompassing an in-depth analysis of mechanism, extensive scope, limitations and wide-ranging applications in diverse organic synthesis, covering the literature from the 21st century. This comprehensive review encapsulates the applications of trifluoromethyl-β-dicarbonyls and their synthetic equivalents as precursors of complex and diverse heterocyclic scaffolds, fused heterocycles and spirocyclic compounds having medicinal and material importance. Their potent synthetic utility in cyclocondensation reactions with binucleophiles, cycloaddition reactions, C-C bond formations, asymmetric multicomponent reactions using classical/solvent-free/catalytic synthesis have been presented. Influence of unsymmetrical trifluoromethyl-β-diketones on regioselectivity of transformation is also reviewed. This review will benefit the synthetic and pharmaceutical communities to explore trifluoromethyl-β-dicarbonyls as trifluoromethyl building blocks for fabrication of heterocyclic scaffolds having implementation into drug discovery programs in the imminent future.

Catalyst-Free One-Pot Three-Component Synthesis of Diversely Substituted 5-Aryl-2-oxo-/thioxo-2,3-dihydro-1H-benzo[6,7]chromeno[2,3-d]pyrimidine-4,6,11(5H)-triones Under Ambient Conditions

A simple, catalyst-free, straightforward, and highly efficient one-pot synthesis of pharmaceutically interesting diverse kind of a new series of functionalized 5-aryl-2-oxo-/thioxo-2,3-dihydro-1H-benzo[6,7]chromeno[2,3-d]pyrimidine-4,6,11(5H)-triones 4 (4-1-4-37) and substituted 5,5'-(1,4-phenylene)bis(2-oxo-/thioxo-2,3-dihydro-1H-benzo[6,7]chromeno[2,3-d]pyrimidine-4,6,11(5H)-trione) derivatives 4' (4'-1-4'-3) has been developed based on a three-component reaction between barbituric acid/N,N-dimethylbarbituric acid/2-thiobarbituric acid (1), aromatic aldehydes (2), and 2-hydroxy-1,4-naphthoquinone (3) in aqueous ethanol at room temperature (25-30 °C). The salient features of this protocol are mild reaction conditions, use of no catalyst, no need of column chromatographic purification, excellent yields, high atom economy, eco-friendliness, easy isolation of products, and reusability of reaction media.

Recent applications of barbituric acid in multicomponent reactions

This review aims to show representative examples of multicomponent reactions utilizing barbituric acid in the synthesis of various heterocyclic structures.