Palladium(II)-catalysed oxidative cyclisation of 2-allylphenols in the presence of copper(II) acetate and molecular oxygen. Oxidation state of palladium in the Wacker-type reaction
Abstract
In the catalytic oxidative cyclisation of 2-(but-2-enyl)phenol (2) by (+)-[(3,2,10-η-pinene)PdOAc]2(1) in the presence of Cu(OAc)2 and O2, the η3-pinene ligand in (1) remains attached to palladium throughout the reaction, an observation which cannot be accounted for by the conventional Wacker-type catalysis.