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Fluorophore substituted boron diketonate 3 shows solvatochromism with a large Stokes shift ranging from 121 nm to 166 nm and emitting strongly in its solid states 3a (463 nm) and 3b (563 nm). Boron diketonate provides a choice of fast turn-off or ratiometric detection of a diamine with respect to the fluorophore substitution on the boron-chelating ring. Naphthyl substituted 3a emission was quenched rapidly and selectively on interaction with ethylenediamine. The detection limit was found to be 0.8 μM. Pyrene substituted 3b exhibited selective calorimetric and ratiometric detection of ethylenediamine with a detection limit of 1.2 μM. Diamine involves a substitution reaction with the elimination of methylsulfanyl group in 3 and it was supported by NMR and mass techniques. The rates of reaction of 3a and 3b with ethylenediamine, Kobs, were determined and found to be 2.18–9.96 × 10−4 s−1 in chloroform. Detection of vaporized diamine over other monoamines under UV-light (365 nm) was achieved with a demonstration of boron diketonate 3 coated silica gel TLC plate test strip array.

The stereo/regio/chemoselective syntheses of a library of novel spiro[acenaphthylene-1,3′-pyrrolizin]-2-one and spiro[acenaphthylene-1,5′-pyrrolo[1,2-c]thiazol]-2-one have been achieved through 1,3-dipolar cycloaddition. Intermediate azomethine ylides generated in situ from α-amino acids and acenaphthylene-1,2-dione react with α-aroylidine ketenedithioacetal (AKDTA) derivatives to give the target product in excellent yield under ultrasound irradiation. Further, spiro-S,S-acetals are converted to spiro-2H-pyranones by a one-pot cyclization strategy.

An efficient route for the synthesis of novel thioether containing dihydropyrano[2,3-c]pyrazoles has been accomplished via a solvent-free, catalyst-free, one-pot, five component domino strategy. This synthetic approach offers several advantages such as an easy work-up, no need for purification techniques and a short reaction time with good atom economy and high yields of the products (81–86%).