Non-steroidal anti-inflammatory drugs, such as ibuprofen and naproxen, are extensively used worldwide for pain relief and other minor aliments such as the common cold. In their Perspective article, Professors Carmen Claver and Cyril Godard from Universitat Rovira I Virgili in Tarragona, Spain, highlight some of the progress made in developing catalysts for the production of starting materials for the large scale production of these drugs.

By using palladium based catalysts, Claver and other chemists attempt to achieve control over the reaction that converts vinylarenes to arylpropionic acids, which can then be used to make the anti-inflammatory drugs.   This control needs to address two points, the regioselectivity and the stereoselectivity.   However, so far, producing catalysts that combine high regioselectivity of the reaction with high stereoselectivity has proved to be elusive.   Claver and Godard describe the achievements to date, and also highlight the challenges still facing chemists working in this area.   In particular, they mention the different types of ligands (monodentate, bidentate, phosphines, P, N ligands) which have all been shown to produce catalysts which have allowed some control.

However, there is still much work to be done in this area. 'While great progress has been made over the last years in controlling the regioselectivity of the alkoxycarbonylation reation', says Claver, ' the stereoselectivity which is crucial in terms of pharmaceutical applications, is still to be largely improved.

Pd-catalysed asymmetric mono- and bis-alkoxycarbonylation of vinylarene