Phenoxaphosphonium Mixed Ylides in Reactions With Alkynes

Abstract The reactivity of ylides possessing additional iodonium functionality is driven by the departure of the iodonium group, which generates highly reactive intermediates. The scope of these reactions depends on both the nature of the reacting partner and the functional groups present at the ylidic center. In this study, we investigate the reactivity of phosphonium–iodonium ylides, where the ylidic carbon atom is bonded to a cyclic phenoxaphosphonium moiety and various electron‐withdrawing substituents. The study examines these ylides in reactions with nitriles and alkynes, continuing our investigation of acyclic phosphonium–iodonium ylides with triple‐bond‐containing compounds. The incorporation of phosphorus into a cyclic structure reveals new bond‐making and bond‐breaking patterns in reactions with alkynes, leading to novel reaction pathway and the formation of enone‐functionalized phosphonates. Phenoxaphosphonium–iodonium ylides and furans have been shown to have antiproliferative activity in vitro against several human cancer cell lines.