Metal-free synthesis of 3-chalcogenyl chromones from alkynyl aryl ketones and diorganyl diselenides/disulfides mediated by PIFA

Abstract

3-Selenyl/sulfenyl chromones/thiochromones were conveniently synthesized from the PIFA-mediated reactions between alkynyl aryl ketones bearing an ortho-methoxy/methylthio group and diorganyl diselenides/disulfides. This metal-free approach is postulated to first undergo the formation of the reactive RSeOCOCF₃ or RSOCOCF₃ from the reaction of diorganyl diselenides or disulfides with PIFA, followed by the electrophilic cyclization of alkynyl aryl ketones enabled by the electrophilic species generated herein.