Confirming the existence of π-allyl-palladium intermediates during the reaction of meta photocycloadducts with palladium(II) compounds

The transient existence of π-allyl-palladium intermediates formed by the reaction of Pd(OAc)2 and anisole-derived meta photocycloadducts has been demonstrated using NMR techniques. The intermediates tended to be short-lived and underwent rapid reductive elimination of palladium metal to form allylic acetates, however this degradation process could be delayed by changing the reaction solvent from acetonitrile to chloroform.