Alkene Hydrosilation by a Cationic Hydrogen-substituted Iridium Silylene Complex

A cationic hydrogen-substituted iridium silylene complex [(PNP)(H)Ir Si(Mes)H][B(C6F5)4] (2) was synthesized via hydride abstraction from the corresponding neutral iridium silyl hydride complex. DFT calculations for 2 indicate that the cationic charge is localized at the silicon center and depict a LUMO with predominant silicon p-orbital character. Notably, complex 2 reacts rapidly with unhindered alkenes at ambient temperatures to afford disubstituted silylene complexes via Si-C bond formation. Complex 2 is also the catalyst for alkene hydrosilation of primary silanes with a high degree of anti-Markovnikov selectivity.