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.
No takes yet. Share an insight, caveat, or question.
Ogawa et al. (1999) studied this question.