2025/07/24 by Pamela Adienes Benzan Lantigua, Mónica Rodrı́guez, Jana Roithová +1 · 1 voice
Chemistry · #Synthesis and characterization of novel inorganic/organometallic compounds #Catalytic Cross-Coupling Reactions #Coordination Chemistry and Organometallics
paper · pdf · doi:10.1002/chem.202501643
Abstract Reductive elimination (RE) is one of the most significant obstacles to developing main‐group catalysts for bond coupling processes based on conventional oxidative addition/reductive elimination steps. Here, we report an electrospray ionisation mass spectrometry (ESI‐MS) study demonstrating RE from Si IV hydrosilicates [(tmim)SiH(OAr R )] − (tmimH 3 = tris(3‐methylindol‐2‐yl)methane) generated in solution by oxidative addition of phenols (Ar R O─H) to an anionic Si II centre (silanide) incorporated in a bicyclic cage structure ([(tmim)Si] − ). The activation energy for the reductive elimination linearly decreased with the increasing electron‐withdrawing character of the aryl substituents, suggesting that a negative charge develops in the para position in the rate‐limiting step (RLS). In agreement with experiments, a DFT study supports an ionic mechanism in which the formation of an ion/molecule complex by transient weakening of the Si─O bond is the RLS, as would be intuitively expected from the developing negative charge in the para position. This is a rare example of direct observation of reductive elimination from Si IV to Si II and, to our knowledge, the first involving anionic species.