Triflate-Enabled Rhodium-Catalyzed Cross-Dehydrogenative Si-N Bond Formation from Hydrosiloxanes.

Area of Science:

• Organometallic Chemistry
• Catalysis
• Silicon Chemistry

Background:

• Hydrosiloxanes are valuable silicon reagents for Si-N bond formation.
• Activation challenges have limited their use in catalysis.
• Rhodium complexes offer potential for Si-N bond formation.

Purpose of the Study:

• To investigate the role of the triflate anion in rhodium-catalyzed Si-N bond formation.
• To explore the reactivity of hydrosiloxanes with secondary amines.
• To elucidate the mechanism of cross-dehydrogenative coupling (CDC).

Main Methods:

• Synthesis and characterization of rhodium complexes with an organosilyl ligand.
• Anion-dependent reactivity studies in CDC reactions.
• Experimental and computational investigations of the catalytic pathway.

Main Results:

• The triflate rhodium complex efficiently catalyzes Si-N bond formation, unlike the chloride analog.
• HSiMe(OSiMe3)2 is identified as a versatile hydrosiloxane reagent.
• An unconventional coordination pathway involving oxygen-atom coordination of hydrosiloxanes is revealed.
• The triflate anion promotes N-H activation via hydrogen bonding.

Conclusions:

• The triflate anion plays a crucial role in activating hydrosiloxanes for Si-N bond formation.
• Ligand hemilability and anion effects are key to designing effective catalytic systems.
• This work provides insights for developing new catalysts for challenging Si-N coupling reactions.