An efficient synthesis of 3-aminochromones and 3-alkylchromones by a N-heterocyclic carbene (NHC) catalyzed intramolecular hydroacylation reaction of corresponding salicylaldehyde derived nitriles and activated alkynes respectively in ionic liquids under microwave conditions is reported. This protocol has the advantages of environmental friendliness, higher yields, shorter reaction times, and convenient operation using the commercially available thiazolium catalyst. The origin of the chemical reactivity of the NHC-catalyzed intramolecular hydroacylation reaction of nitriles is studied using Density Functional Theory (DFT). The results suggest that 3-aminochromone formation occurs via an acyl anion intermediate called a Breslow intermediate (INT2) through TS2. The Breslow intermediate (INT2) forms a carbon–carbon bond with the nitrile carbon to produce an imine intermediate INT3viaTS3, which further undergoes imine to amine tautomerism to give the end product. Some of the derivatives of 3-aminochromone are subjected to amine functionalization in one pot to obtain a library of compounds for anticancer activity. Among the investigated compounds, 2c (SVM-2), 4c (SVM-4) and 2d (SVM-9) show IC₅₀ values of 5.18, 4.89 and 27.3 μM respectively in HeLa S3 cancer cells. Compound 5c (SVM-5) shows IC₅₀ values of 13.3 and 14.2 μM in A549 and HeLa S3 cancer cells, respectively. Compounds 2c (SVM-2) and 4c (SVM-4) produce morphological changes and control the colony formation in HeLa S3 cells, which indicates that these small molecules are potential candidates for anticancer drugs.

We present the short synthesis of the suitably functionalized enantioselective dihydropyran core of secoiridoids using an N-heterocyclic carbene (NHC) catalyzed Coates-Claisen rearrangement mechanism. The key steps of the synthesis are (i) the highly enantioselective NHC catalyzed Coates-Claisen rearrangement for the dihydropyran core, (ii) the assembly of the target dihydropyran core structure of oleuropein from a highly diastereoselective exocyclic trans alkene, and (iii) the highly stereoselective assembly of a monoterpene elenolide core structure.

A simple and efficient direct radical C-2 arylation of 3-aminochromone derivatives with aryl hydrazine is described. The aryl hydrazine acts as an initiator and source for the aryl radical via the cleavage of the C–N bond of aryl hydrazine. The reaction proceeds via a base-promoted single electron transfer (SET) pathway. The aryl radical abstracts a single electron from 3-aminochromone, which generates a C₂-radical iminium ion to undergo a cross-coupling reaction with an aryl radical, and this process offers an array of regioselective 2-aryl substituted 3-aminochromones.