Kaeffer Nicolas, Liu Hsueh-Ju, Lo Hung-Kun, Fedorov Alexey, Copéret Christophe
ETH Zürich , Department of Chemistry and Applied Biosciences , Vladimir-Prelog-Weg 1-5 , CH-8093 , Zürich , Switzerland . Email:
Chem Sci. 2018 May 23;9(24):5366-5371. doi: 10.1039/c8sc01924j. eCollection 2018 Jun 28.
We report a surface organometallic route that generates copper nanoparticles (NPs) on a silica support while simultaneously passivating the silica surface with trimethylsiloxy groups. The material is active for the catalytic semihydrogenation of phenylalkyl-, dialkyl- and diaryl-alkynes and displays high chemo- and stereoselectivity at full alkyne conversion to corresponding ()-olefins in the presence of an N-heterocyclic carbene (NHC) ligand. Solid-state NMR spectroscopy using the NHC ligand C-labeled at the carbenic carbon reveals a genuine coordination of the carbene to Cu NPs. The presence of distinct Cu surface environments and the coordination of the NHC to specific Cu sites likely account for the increased selectivity.
我们报道了一种表面有机金属路线，该路线可在二氧化硅载体上生成铜纳米颗粒（NPs），同时用三甲基硅氧基对二氧化硅表面进行钝化。该材料对苯基烷基、二烷基和二芳基炔烃的催化半氢化反应具有活性，并且在N-杂环卡宾（NHC）配体存在下，在炔烃完全转化为相应的（）-烯烃时表现出高化学选择性和立体选择性。使用在卡宾碳上标记有C的NHC配体的固态核磁共振光谱揭示了卡宾与铜纳米颗粒的真实配位。不同的铜表面环境的存在以及NHC与特定铜位点的配位可能是选择性增加的原因。
