Microwave or Visible Light‐Induced Annulation of Diazo(phenyl)methyl(diphenyl)phosphine Oxide and Chalones

Abstract Chemo‐ and stereoselectivities in microwave or visible light‐induced reactions of diazo(phenyl)methyl(diphenyl)phosphine oxide and chalcones were investigated. The results indicate that diazo(phenyl)methyl(diphenyl)phosphine oxide first generates triphenylphosphene, which undergoes both [4 + 2] and [2 + 2] annulations with chalcones. The former gives rise to a pair of diastereomeric δ‐phostines, while the later yields unstable β‐phostines, which further proceed a Wittig‐like reaction to produce dienes and arylphosphine dioxide. The current investigation provides a full understanding on the reaction of phosphene and chalcones and improved yields.