Reaction of carbon monoxide with strained alkenes catalyzed by a cationic palladium(II) complex

Abstract

The reaction of carbon monoxide with strained alkenes such as norbornene, dicyclopentadiene and bicyclo[2.2.2]oct-2-ene catalyzed by a cationic palladium complex [Pd(MeCN) 2(PPh 3) 2](BF 4) 2 has been studied. Normally, 2:2 cooligomers having enol lactone structure and 3:3 cooligomers having ketal lactone structure were obtained. A mechanism involving alternate insertion of alkene and carbon monoxide into an initial Pd–H bond followed by enolization–cyclization is proposed.