Iridium- and Rhodium-Catalyzed Dehydrogenative Silylations of C(sp<sup>3</sup>)H Bonds Adjacent to a Nitrogen Atom Using Hydrosilanes
作者:Tsuyoshi Mita、Kenichi Michigami、Yoshihiro Sato
DOI:10.1002/asia.201300930
日期:2013.12
silylated: In the presence of iridium or rhodium catalysts, C(sp3)H bonds adjacent to a nitrogen atom were silylated by the aid of a pyridine‐directing group. In iridium catalysis, a hydrogen‐trapping reagent such as norbornene or tert‐butylethylene, which is usually required in late transition‐metal‐catalyzeddehydrogenative coupling reactions, was not required. In rhodium catalysis, however, 1 equivalent
spirocyclic NHC Ir(III) complex (SNIr), generating a variety of heteroarylsilanes. A significant advantage of this catalytic system is that multiple types of intermolecular C–H silylation can be achieved using one catalytic system at α, β, γ, or δ positions of heteroatoms with excellent regioselectivities. Mechanistic experiments and DFT calculations indicate that the polycyclic ligand of SNIr can form an