ESI-MS mechanistic studies of Wacker oxidation of alkenes: dinuclear species as catalytic active intermediates

Abstract

The monitoring, by ESI-MS, of the Wacker oxidation of alkenes, using benzoquinone as terminal oxidant, has shown that dinuclear palladium complexes are more involved as active catalytic intermediates than mononuclear species. Kinetic experiments have confirmed a palladium-dependency greater than first-order, pointing out that the catalytic active species are formed by an associative process. The ESI-MS analysis associated with tests of complexation has also shown that the reoxidation of Pd occurs before the decoordination of the product.