- Is it possible to use silicon complexes (highly abundant element) as catalysts instead of precious transition metal complexes ?
Vast fundamental research in organometallic chemistry (coordination chemistry, ligand effects, reactivity, etc…) contributes enormously to development of efficient homogeneous catalysts to achieve highly selective reactions under mild conditions, which are difficult or even impossible to process in the absence of catalysts. However, in spite of the significant importance of organometallic catalysts, the principal problem is the highly limited natural resources of precious transition metals.
In contrast, silicon is the second most abundant element in the Earth’s crust mainly found as silicon dioxide (sand or quartz), and other more complex silicate minerals. In other words, the natural resource of silicon is incomparable to that of transition metals and is almost unlimited. This is why silicon is an important element in material chemistry and industry (polymers, rubber, semiconductors).
What about using silicon as catalyst instead of transition metals ?
To the best of our knowledge, real success in chemistry with such a vision has never been achieved. The success of this project should open a new wide research domain in chemistry and could change the vision of catalysis.
In order to address this challenging subject, we actually develop new low valent silicon complexes. Particularly, we recently demonstrated that phosphine-stabilized silylene complexes show transition metal like behavior towards olefins such as reversible binding on the silicon centre (Angew. Chem. Int. Ed. 2011, 50, 10414) as well as reversible insertion / b-elimination processes (Angew. Chem. Int. Ed. 2013, 52, 8437). These reactions are comparable with some key steps of certain catalytic reactions (hydrogenation, hydrosilylation or polymerization).