Hydroarylation of unsaturated carbon-carbon bonds in cross-conjugated enynones under the action of superacid CF3SO3H or acidic zeolite HUSY. Reaction mechanism and DFT study on cationic intermediate speciesElectronic supplementary information (ESI) available: Copies of 1H, 13C, 19F NMR spectra of compounds; X-ray data; data of DFT calculations. CCDC 1847444, 1847451, 1847452, 1847453, 1847454 and 1847456. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8ob01

Reactions of cross-conjugated enynones,1,5-diarylpent-1-en-4-yn-3-ones, with arenes in the system TfOH-pyridine or under the action of acidic zeolite HUSY lead regioselectively to products of hydroarylation of the acetylene bond only,1,1,5-triarylpent-1,4-dien-3-ones, in yields up to 98%. These dienones add one more arene molecule to the double carbon-carbon bond in neat TfOH forming 1,1,5,5-tetraarylpent-1-en-3-ones in high yields. Cationic reaction intermediates have been studied by means of DFT calculations to elucidate plausible reaction mechanisms. Reactions of enynones with arenes in TfOH-Py or with zeolite HUSY lead to products of hydroarylation of the acetylene bond.