(Pc-L) proves capable of promoting carbene SiH bondinsertions using diazo compounds as the carbene source. This catalytic system showed broad scope and a remarkable robustness as indicated by high TON numbers (up to 30000). Moreover, the use of enynones as carbene sources proved also feasible in hydrosilane insertion using this catalytic system. Finally, the insertion in OH and NH bonds of phenols and
Fe<sup>II</sup>-catalysed insertion reaction of α-diazocarbonyls into X–H bonds (X = Si, S, N, and O) in dimethyl carbonate as a suitable solvent alternative
作者:Nour Tanbouza、Hoda Keipour、Thierry Ollevier
DOI:10.1039/c9ra07203a
日期:——
The insertion reaction of a broad range of diazo compounds into Si–H bonds was found to be efficiently catalysed by Fe(OTf)2 in an emerging green solvent i.e. dimethyl carbonate (DMC). The α-silylated products were obtained in good to excellent yields (up to 95%). Kinetic studies showed that the extrusion of N2 to form an iron carbene intermediate is rate-limiting. The iron-catalysed insertion reaction
Effect of Tethered, Axial Thioether Coordination on Rhodium(II)-Catalyzed Silyl-Hydrogen Insertion
作者:William Sheffield、Anthony Abshire、Ampofo Darko
DOI:10.1002/ejoc.201900977
日期:2019.10.9
Dirhodium paddlewheel complexes with tethered thioether ligands are evaluated in diazo‐mediated Si–H insertion reactions. The presence of the thioether groups improved yields at elevated temperatures and allowed greater selectivity for diazo compounds compared to non‐thioether tethered catalysts. Computational modelling helped to rationalize the results.
Metal-Free Insertion Reactions of Silanes with Aryldiazoacetates
作者:Feifei He、Fang Li、Rene M. Koenigs
DOI:10.1021/acs.joc.9b02605
日期:2020.1.17
Si-H insertion reactions represent an important method for the efficient construction of new C-Si bonds, and typically, they are conducted in the presence of metal catalysts. In this report, we describe a photochemical approach that now allows the insertion of carbenes into the Si-H bond of silanes under metal-free reaction conditions (23 examples, up to 83% yield).
The X-ray structural analyses of homoleptic Rh(II) complexes made of enantiopure (R)-1,1′-binaphthyl and (R)-(5,5′,6,6′,7,7′,8,8′-octahydro)binaphthyl phosphate ligands are for the first time presented. The possibility to introduce halogen atoms at the 3,3′-positions is also reported. The isolated dirhodiumcomplexes were further tested as catalysts (1 mol %) in enantioselective cyclopropanations and