Iron replaces precious metals

Oeiras, 26.04.2012

Chemical processes require rare metal catalysts for producing, for example, pharmaceuticals. But increasing prices and limited availability of precious metals has pressured researchers to look for cheaper alternatives. In this line, ITQB chemists from the Homogeneous Catalysis Lab have managed to design a new type of equally efficient catalysts using iron instead. The synthesis process is described in Chemical Communications and highlighted on the journal’s cover.

Synthesising new compounds is like building a complex jigsaw puzzle where every new piece is a challenge. Each step is a particular chemical reaction that requires the presence of specific materials – catalysts – to happen. Up till now, most catalysts able to perform the reduction of organic functional groups were based on precious metals such as palladium, rhodium, iridium, and ruthenium. But global efforts in sustainability, coupled with increasing prices and limited availability of precious metals, are turning the attention to readily available biocompatible metals, such as iron. In this work, researchers were able to devise an easy strategy to convert a commercially available iron compound into a novel organometallic iron complex displaying remarkable catalytic activity in the selective reduction of sulfoxides. The mechanism, involving the C-H activation of imidazolium salts, is unique in iron chemistry.

Original Paper

Chem. Commun, 2012, 48, 4944-4946

Unprecedented synthesis of iron NHC complexes by C-H activation of imidazolium salts. Mild catalysts for reduction of sulfoxides

João M. S. Cardoso and Beatriz Royo