Selective sequential addition of diphenyl diselenide to ethyl propiolate and isocyanides upon irradiation with near-UV light

Upon irradiation through Pyrex with a tungsten lamp (hν>300 nm), diphenyl diselenide adds to electron-deficient alkynes such as ethyl propiolate and isocyanides sequentially to provide the corresponding three-component coupling products in moderate to high yields selectively. The appropriate strength of carbon-radical trapping by diphenyl diselenide facilitates its selective three-component coupling with ethyl propiolate and isocyanides.