Bsi(OTf)3-mediated tandem annulation of 1-aryl isochroman-3-ones with oxygenated arenes: one-pot synthesis of polyoxygenated homotriptycenes

Abstract

Bi(OTf)₃ (bismuth triflate)-mediated one-pot tandem annulation of oxygenated 1-aryl isochroman-3-ones with oxygenated arenes provides polyoxygenated homotriptycenes in moderate to good yields in MeNO₂ at reflux (101 °C) for 10 h under an air atmosphere and easy-operational conditions via intermolecular and intramolecular Friedel–Crafts type procedures. A plausible mechanism is proposed and discussed. This protocol provides a highly effective ring-closure via three carbon–carbon (C–C) bond formations.