Diels-Alder reaction of tetraarylcyclopentadienones with benzo[b]thiophene dioxides in xylenes at reflux led to the formation of tetra aryl-substituted dibenzothiophene as well as penta aryl-substituted benzene analogues depending on the influence...

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Annulative π‐extension of benzothiophene S,S‐dioxide analogues has been achieved via Diels‐Alder reaction of symmetrical 1,3‐diaryl/heteroarylbenzo[c]furans with benzothiophene S,S‐dioxides in toluene at reflux followed by PTSA‐mediated deoxygenation reaction. Employing this one‐pot π‐extension protocol, synthesis of complex seven and nine member heteroacenes was also achieved.

Heteroarylmethylenephosphorus ylides underwent Michael addition with alkynediones and alkynediesters, followed by intramolecular cyclization and elimination of triphenylphosphine oxide to afford 1,2-diaroylbenzenes and 1,2-alkoxy­carbonylcarbo- and heterocycles. The analogous (4 + 2) cycloaddition led to the formation of 2,3-diaroylquinolines.