Alkene hydrosilation by a cationic hydrogen-substituted iridium silylene complex

Area of Science:

• Organometallic Chemistry
• Catalysis
• Silicon Chemistry

Background:

• Iridium complexes are valuable in catalysis.
• Silylene complexes offer unique reactivity pathways.
• Understanding cationic silylene behavior is crucial for developing new transformations.

Purpose of the Study:

• To synthesize and characterize a cationic iridium silylene complex.
• To investigate its electronic structure and reactivity.
• To explore its catalytic applications in hydrosilation and C-Si bond formation.

Main Methods:

• Synthesis of a cationic iridium silylene complex via hydride abstraction.
• Density Functional Theory (DFT) calculations to analyze electronic structure.
• Reaction studies with alkenes and silanes to evaluate catalytic activity.

Main Results:

• Successful synthesis of the cationic iridium silylene complex [(PNP)(H)Ir Si(Mes)H][B(C6F5)4].
• DFT calculations revealed cationic charge localization at silicon and LUMO with silicon p-orbital character.
• The complex reacts readily with alkenes to form disubstituted silylene complexes.
• It acts as an effective catalyst for anti-Markovnikov hydrosilation of primary silanes.

Conclusions:

• The synthesized cationic iridium silylene complex exhibits unique electronic properties and reactivity.
• It enables efficient Si-C bond formation with alkenes.
• It serves as a potent catalyst for selective alkene hydrosilation.