1361973-48-9Relevant academic research and scientific papers
Rhodium carbene complexes as versatile catalyst precursors for Si-H bond activation
Krueger, Anneke,Albrecht, Martin
, p. 652 - 658 (2012)
Rhodium(III) complexes comprising monoanionic C,C,C-tridentate dicarbene ligands activate Si-H bonds and catalyse the hydrolysis of hydrosilanes to form silanols and siloxanes with concomitant release of H2. In dry MeNO2, selective formation of siloxanes takes place, while changing conditions to wet THF produces silanols exclusively. Silyl ethers are formed when ROH is used as substrate, thus providing a mild route towards the protection of alcohols with H2 as the only by-product. With alkynes, comparably fast hydrosilylation takes place, while carbonyl groups are unaffected. Further expansion of the Si-H bond activation to dihydrosilanes afforded silicones and polysilyl ethers. Mechanistic investigations using deuterated silane revealed deuterium incorporation into the abnormal carbene ligand and thus suggests a ligand-assisted mechanism involving heterolytic Si-H bond cleavage. Ligand-assisted Si-H bond cleavage: Rhodium-catalysed Si-H bond activation provides a methodology for the silyl group to be transferred to oxygen centres, thus providing access to siloxanes and silanols (using H 2O), alkoxysilanes (using ROH) and to polysiloxanes, such as silicones, when using difunctional silanes. The process is pH neutral, avoids sensitive silylating agents and produces H2 as useful and exclusive side product. Copyright
