Design and synthesis of a novel tetraphenylethene-2-pyrone (TPEP) conjugate exhibiting donor-acceptor characteristics is reported. The localized frontier molecular orbitals (DFT studies) and the solvent polarity dependent photoluminescence characteristics directly corroborate the presence of intramolecular charge transfer character in TPEP. TPEP is poorly emissive in the solution state. In contrast, upon aggregation (THF/water mixtures), TPEP exhibits aggregation-induced emission enhancement. Upon aggregation, dyad TPEP forms a fluorescent nanoaggregate which was confirmed by transmission electron microscopy imaging studies. The luminescence nanoaggregates were elegantly exploited for selective detection of nitro aromatic compounds (NACs). It was found that nanoaggregates of TPEP were selectively sensing the picric acid over the other NACs. Efficiency of the quenching process was further evaluated by the Stern-Volmer equation. TPEP-based low-cost fluorescent test strips were developed for the selective detection of picric acid.

A process suitable for kilogram-scale synthesis of (2R)-2-methyl-6-nitro-2-{[4-(trifluoromethoxy)phenoxy]methyl}-2,3-dihydroimidazo[2,1-b][1,3]oxazole (DNDI-VL-2098, 2), a preclinical drug candidate for the treatment of visceral leishmaniasis, is described. The four-step synthesis of the target compound involves the Sharpless asymmetric epoxidation of 2-methyl-2-propen-1-ol, 8. Identification of a suitable synthetic route using retrosynthetic analysis and development of a scalable process to access several kilograms of 2 are illustrated. The process was simplified by employing in situ synthesis of some intermediates, reducing safety hazards, and eliminating the need for column chromatography. The improved reactions were carried out on the kilogram scale to produce 2 in good yield, high optical purity, and high quality.

An efficient regioselective three-component synthesis of bipyr-azoles4 by reaction of a-aroylidineketene dithioacetals 1, Bestmann-Ohira reagent 2 a and hydrazine hydrate 3 using KOH as a base in methanol medium was reported. Salient features of the present methodology are theregioselective construction of two pyrazoles unit contains four different heteroatoms (nitrogen, oxygen, sulfur and phosphorous) under mild reaction conditions with excellent yield in a single operation. In addition, unusual demethylation of methyl phosphorous ester group was observed. Based on the control experiments, plausible reaction mechanism was proposed.

The iminopyrans were synthesized by the CuAAC‐MCR approach, the coupling of enaminones, phenyl acetylenes, and sulfonyl, under microwave treatment. The mechanism of the formation of iminopyrans along with amidine has been studied in detail. Experiments to minimize amidine formation were explored, and unfortunately, these experiments were unsuccessful. Molar equivalents of enaminones, phenyl acetylenes, and sulfonyl were optimized to increase the yield of iminopyran. Fluorescent properties of iminopyrans were characterized using Frontier molecular orbital analysis, UV absorption, and emission studies.

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