Allylic oxidation of alkenes with palladium catalysts

Studies of the Pd-catalysed alkene oxidation to allylic, vinylic, and homoallylic esters are summarized. The regioselectivity and mechanism of stoichiometric reactions between alkenes and Pd-II through the pi- and sigma-complexes are discussed, with particular emphasis on the ligand and solvent effects. Two different pathways of the Pd-catalysed oxidative esterification of alkenes are considered: (i) stepwise Pd-II/Pd-0 reactions, (ii) reactions mediated by low-valence Pd giant clusters modeling the active component of hetreogeneous Pd catalysts. (C) 2004 Elsevier B.V. All rights reserved.