Synthesis of Chalcogenylchromenes through Cyclization of Propargylic Aryl Ethers

We
describe here for the first time the synthesis of 2-(chalcogenyl)-3H-benzo[f]chromenes and the new 3-(phenylselanyl)-2H-chromenes by the radical or electrophilic cyclization
of propargylic aryl ethers in the presence of diorganyl diselenides
or ditellurides using Oxone as a green oxidant and acetonitrile as
solvent in a sealed tube at 100 °C. In this study, thirty-one
chalcogenylchromenes with a broad substrate scope were prepared in
moderate to excellent yields (50–98%), including compounds
derived from natural products.