Iron-Catalysed Chemo-, Regio-, and Stereoselective Hydrosilylation of Alkenes and Alkynes using a Bench-Stable Iron(II) Pre-Catalyst
作者:Mark D. Greenhalgh、Dominik J. Frank、Stephen P. Thomas
DOI:10.1002/adsc.201300827
日期:2014.2.10
AbstractThe chemo‐, regio‐, and stereoselective iron‐catalysed hydrosilylation of alkenes and alkynes with excellent functional group tolerance is reported (34 examples, 41–96% yield). The catalyst and reagents are commercially available and easy to handle, with the active iron catalyst being generated in situ, thus providing a simple and practical methodology for iron‐catalysed hydrosilylation. The silane products can be oxidised to the anti‐Markovnikov product of olefin hydration, and the one‐pot iron‐catalysed hydrosilylation–oxidation of olefins to give silane(di)ols directly is also reported. The iron pre‐catalyst was used at loadings as low as 0.07 mol%, and displayed catalyst turnover frequencies (TOF) approaching 60,000 mol h−1. Initial mechanistic studies indicate an iron(I) active catalyst.magnified image
Activation and discovery of earth-abundant metal catalysts using sodium tert-butoxide
作者:Jamie H. Docherty、Jingying Peng、Andrew P. Dominey、Stephen P. Thomas
DOI:10.1038/nchem.2697
日期:2017.6
NaOtBu — an alkoxide salt — enables simple access to low-oxidation-state catalysis using sustainable first-row transition metals (Fe, Co, Mn, Ni). The approach works across a widerange of reductive alkene and alkyne functionlization reactions including hydroboration, hydrosilylation, hydrogenation, hydrovinylation and [2π+2π] cyclization reactions.
AbstractSilanes are important in chemistry and material science. The self‐redistribution of HSiCl3 is an industrial process to prepare SiH4, which is widely used in electronics and automobile industries. However, selective silane cross‐redistribution to prepare advanced silanes is challenging. We now report an enthalpy‐driven silane cross‐redistribution to access bis‐silanes that contain two different types of Si−H bonds in the same molecule. Compared with entropy‐driven reactions, the enthalpy‐driven reaction shows high regioselectivity, broad substrate scope (62 examples) and high atom economy. Our combined experimental and computational study indicates that the reaction proceeds through a Ni0‐NiII‐NiIV catalytic cycle.