Highly Selective Three-Component Coupling of Ethyl Propiolate, Alkenes, and Diphenyl Diselenide under Visible-Light Irradiation
Abstract
Just the right strength of carbon-radical trapping by diphenyl diselenide facilitates its selective three-component coupling with an electron-poor alkyne and an electron-rich alkene [Eq. (1)]. In contrast, (PhS)2 is too weak and (PhTe)2 too strong a radical trap, and polymerization of the unsaturated compounds and addition of (PhTe)2 to the alkyne occur, respectively.