Base-Promoted Selective Synthesis of 2-Pyranones and Tetrahydronaphthalenes via Domino Reactions.

A highly efficient domino protocol has been developed for the synthesis of 6-aryl-4-(methylthio/amine-1-yl)-2-oxo-2-pyran-3-carbonitriles and 4-aryl-2-(amine-1-yl)-5,6,7,8-tetrahydronaphthalene-1-carbonitriles from simple and readily available α-aroylketene dithioacetals, malononitrile, secondary amines, and cyclohexanone. This elegant domino process involved consecutive addition-elimination, intramolecular cyclization, and ring opening and closing sequences. Notably, in situ generated 2-imino-4-(methylthio/amine-1-yl)-6-aryl-2-pyran-3-carbonitrile plays multiple roles in the construction of various novel polyaromatic hydrocarbons.

Tetraphenylethene-2-Pyrone Conjugate: Aggregation-Induced Emission Study and Explosives Sensor.

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.