Palladium-Catalyzed -Arylation of Acylketene Synthons with Aryl Chlorides Enabled by Ylide-Functionalized Phosphines (YPhos)

A catalyst system based on palladium 2-methylnaphthyl complexes bearing ylide-functionalized phosphines (YPhos) was found to enable the selective gamma-arylation of 1,3-dioxinone derivatives with diversely functionalized aryl, heteroaryl, and vinyl chlorides. The products were further converted into 1,3-diketones and heterocycles, highlighting their function as synthetic hubs. Experimental and computational studies revealed that bulky, electron-rich YPhos ligands are uniquely effective because they enable the oxidative addition of aryl chlorides at room temperature while at the same time efficiently promoting the rate-limiting reductive elimination step of the thermally sensitive enolates.