Kandasamy Rajaguru

Erbium triflate promoted multicomponent synthesis of highly substituted imidazoles.

The synthesis of highly substituted imidazole derivatives has been achieved from various α-azido chalcones, aryl aldehydes, and anilines. This multicomponent protocol employs erbium triflate as a catalyst resulting in excellent yield of the imidazoles.

Hypervalent Iodine(III) Mediated Synthesis of 3-Substituted 5-Amino-1,2,4-thiadiazoles through Intramolecular Oxidative S–N Bond Formation

An efficient synthesis of 3-substituted-5-arylamino-1,2,4-thiadiazoles through intramolecular oxidative S-N bond formation of imidoyl thioureas by phenyliodine(III) bis(trifluoroacetate) is reported. The protocol features a metal-free approach, broad substrate scope, very short reaction times, good to excellent yields, and simple starting materials.

Boranil dye based “turn-on” fluorescent probes for detection of hydrogen peroxide and their cell imaging application

The synthesis of boranil dye fluorescent probes for the detection of hydrogen peroxide has been described. The probes exhibited high selectivity in sensing hydrogen peroxide among other reactive oxygen species, reactive nitrogen species and biologically pertinent species. The probes display good sensitivity and a rapid response time. The sensing mechanism was ascertained by ESI-MS analysis and density functional theory (DFT) calculations. The probes have been successfully applied for imaging of H2O2 in HeLa cells under physiological conditions.

A direct green route towards the synthesis of 2-aroyl-3,5-diarylthiophenes from 1,5-diketones

The synthesis of 2-aroyl-3,5-diarylthiophenes has been achieved from various 1,5-diketones with elemental sulphur and morpholine under efficient microwave conditions. The reaction follows a green protocol involving solvent-free conditions, short reaction time, and simple work-up avoiding chromatographic purification.

Investigation on the reactivity of α-azidochalcones with carboxylic acids: Formation of α-amido-1,3-diketones and highly substituted 2-(trifluoromethyl)oxazoles

Summary The reaction of α-azidochalcones with carboxylic acids has been investigated resulting in the formation of α-amido-1,3-diketones under microwave irradiation via in situ formation of 2H-azirine intermediates. An interesting reaction is described wherein, with trifluoroacetic acid at lower temperature, it affords highly substituted 2-(trifluoromethyl)oxazoles. These flexible transformations proceed under solvent free conditions in good to excellent yields without any catalyst.

Divergent reactivity of α-azidochalcones with metal β-diketonates: tunable synthesis of substituted pyrroles and indoles

A divergent reactivity of α-azidochalcones with metal β-diketonates for the synthesis of substituted pyrroles and indoles is described. Metal β-diketonates have been applied as bifunctional reactive partners. With a copper complex, the synthesis of substituted pyrroles in micellar media via 2H-azirine intermediates has been achieved under mild conditions, while with Fe(acac)2 as a catalyst, the reaction proceeds smoothly to yield indoles regioselectively.