Theoretical investigations on the activation of Silanes by rare-earth complexes: Mechanisms, bonding, and catalytic implications

The activation of E–H bonds (E = Si, B, C, etc.) by rare-earth complexes has emerged as a central topic in organometallic chemistry, due to its mechanistic diversity and its relevance to catalytic transformations. Among these, the cleavage and functionalization of silanes (Si H) by lanthanide and related complexes have drawn increasing attention, both experimentally and theoretically. Recent computational studies have unveiled a wealth of mechanistic insights, revealing that σ-bond metathesis constitutes the dominant pathway for Si H activation across most rare-earth elements, contrasting with oxidative addition mechanisms typical of transition metals. This review summarizes theoretical developments devoted to the activation of silanes by rare-earth complexes, emphasizing density functional theory (DFT) analyses, bonding descriptions, and trends across the lanthanide series. Theoretical models, including Cp₂LnH and bis(amidinate) systems, are discussed in connection with experimental data, providing a coherent picture of structure–reactivity relationships. Finally, perspectives on ligand effects, periodic trends, and catalytic applications are outlined to guide future design of rare-earth-based hydrosilylation catalysts. • Density functional theory provides a unified mechanistic understanding of Si H activation by rare-earth complexes. • σ-Bond metathesis is confirmed as the dominant pathway across lanthanides, with barriers governed by Lewis acidity and ligand sterics. • Alternative mechanisms (σ-complex assisted, heterolytic, radical) emerge in specific ligand and metal environments. • Periodic trends rationalize enhanced reactivity from La to Lu and the exceptional behavior of Sc. • Theoretical insights enable rational design of rare-earth catalysts for hydrosilylation and small-molecule activation.