Computational and Experimental Investigation of Alkene Hydrogenation by a Pincer-Type [P2Si]Rh Complex: Alkane Release via Competitive σ‑Bond Metathesis and Reductive Elimination

A combined experimental and computational approach has been utilized to elucidate the mechanism of alkene hydrogenation by pincer-type [P2Si]Rh catalysts. Although [P2Si]Rh interacts with H2 to afford a dihydrogen σ-complex rather than a dihydride (seemingly an indication of facile reductive elimination from Rh­(III)), alkane release occurs by competitive σ-bond metathesis (bimolecular) and reductive elimination (unimolecular) pathways. This unusual behavior is attributed to the strong trans influence of the silyl donor.