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Updated: Aug 23, 2025

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
Synthesis of Chalcogenylchromenes through Cyclization of Propargylic Aryl Ethers
Paola S Hellwig1, Angelita M Barcellos1, Roberta Cargnelutti2
1Laboratório de Síntese Orgânica Limpa - LASOL, CCQFA, Universidade Federal de Pelotas - UFPel, P.O. Box 354 - 96010-900, Pelotas, RS, Brazil.
Abstract:
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.
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