New N-heterocyclic carbene complexes for catalytic hydrosilylation and organometallic chemistry

A new generation of N-heterocyclic carbene platinum catalysts has been developed for the hydrosilylation of alkenes, alkynes and allenes. These complexes possess high activities and display exquisite stereoselectivities whilst being efficient at low catalyst loadings. They tolerate a wide range of functional groups and the precatalyst precursor is readily available, insensitive towards air and moisture, bench-stable for extended periods of time and easy to handle. These qualities make them the ideal user-friendly catalysts for hydrosilylation. In general, all the reagents are mixed directly from their bottles and stirred in air without any precaution. Furthermore, the use of solventless conditions, coupled with a fully atom-economical transformation, leads to a true green process, attractive for industry. Additionally, an exceptionally bulky N-heterocyclic carbene has been designed, fully characterized and engaged in the formation of several organometallic complexes. IPr*(2-Np) appears to be the most sterically demanding NHC reported to date. It is noteworthy that its ability to modify its overall shape enables IPr*(2-Np) to accommodate various coordination environments whilst still remaining one of the most sigma-donating NHCs.