Cation-Assisted Hydrosilylation of Alkynes Catalyzed by a Low-Valent Iron Complex Bearing Noninnocent Ligands

The field of iron catalysis often faces hurdles in accommodating its transient and unstable low-valent intermediates. By harnessing the noninnocent character of commercial bathocuproine ligand, we managed to develop a reliable functionalization of alkynes with primary, secondary, and tertiary silanes but also with germanium hydrides, catalyzed by a low-valent iron complex. The robustness of the catalyst enabled gram-scale synthesis of vinylsilanes, low catalytic loading, one-pot, hetero, bis-hydrosilylation, but also high steric build-up. Mechanistic studies suggest an important effect of the MgII cation resulting from the reduction of the precatalyst, by assisting the dynamic generation of a highly reactive, under-coordinated iron species from a stable complex.