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

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.