Air-Stable Secondary Phosphine Oxide as Preligand for Palladium-Catalyzed Intramolecular α-Arylations with Chloroarenes

A palladium catalyst derived from air-stable secondary phosphine oxide (1-Ad)<sub>2</sub>P(O)H enabled efficient intramolecular α-arylations of amides with aryl chlorides, which allowed for the synthesis of diversely substituted (aza)oxindoles.