The development of an enantioselective nickel hydrosilylation catalyst system via multi-substrate screening

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• 作者：Torsten Irrgang ; Thomas Schareina and Rhett Kempe
• 关键词：Asymmetric catalysis ; Hydrosilylation ; Ketones ; Multi-substrate screening ; Nickel ; P ligands
• 刊名：Journal of Molecular Catalysis A: Chemical
• 出版年：2006
• 出版时间：1 September 2006
• 年：2006
• 卷：257
• 期：1-2
• 页码：48-52
• 全文大小：167 K

文摘

Multi-substrate screening (asymmetric hydrosilylation of ketones) comparing the catalytic behaviour of Ru, Ni, Pd, Rh and Ir DIOP-catalyst systems [DIOP = O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane] was performed. Initial screening studies revealed that beside the well explored rhodium complexes nickel-based catalysts show interesting selectivity and activity. Mechanistic studies indicate a long induction period in which the active and selective catalyst is formed. [Ni(DIOP)₂] which X-ray crystal structure was determined is not active under the applied conditions. Optimisation of the catalyst behaviour concluded from the mechanistic studies led to an improvement of the enantioselectivity by around 20 % in comparison to the multi-substrate screening results.