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.

Investigating the photochemical properties of an arenyl dienol.

Upon irradiation with UV light, an arenyl dienol was transformed into linear and angular meta photocycloadducts and ortho derived photoadducts. Extended exposure to UV radiation resulted in the formation of other degradation products, which shed light on the chemical processes taking place. One of the linear meta photocycloadducts was thermally unstable and underwent further thermal and photochemical transformation, while the ortho-derived photocycloadducts ring-opened and eliminated methanol to afford a cyclooctadienone product.

Investigating the arenyl-diene double [3 + 2] photocycloaddition reaction.

The double [3 + 2] photocycloaddition reaction involving arenyl-dienes has been used to assemble seven separate [5.5.5.