A Pentacoordinate Mn(II) Precatalyst That Exhibits Notable Aldehyde and Ketone Hydrosilylation Turnover Frequencies
作者:Chandrani Ghosh、Tufan K. Mukhopadhyay、Marco Flores、Thomas L. Groy、Ryan J. Trovitch
DOI:10.1021/acs.inorgchem.5b01825
日期:2015.11.2
found to possess an intermediate-spin (S = 3/2) Mn(II) center by the Evans method and electron paramagnetic resonance spectroscopy. Furthermore, (κ5-N,N,N,N,N-PyEtPDEA)Mn was determined to be an effective precatalyst for the hydrosilylation of aldehydes and ketones, exhibiting turnover frequencies of up to 2475 min–1 when employed under solvent-free conditions. This optimization allowed for isolation
在吡啶取代的双(亚氨基)吡啶配体PyEt PDI存在下加热(THF)2 MnCl 2,制备相应的二卤化物配合物(PyEt PDI)MnCl 2。使用过量的Na / Hg的这种前体的还原导致螯合物甲基基团的脱质子化,得到双(烯酰胺)三(吡啶) -支持的产品,(κ 5 - Ñ,Ñ,Ñ,Ñ,ñ - PyEt PDEA)的Mn 。该配合物通过单晶X射线衍射表征,发现具有中间自旋(S = 3 /2)通过Evans方法和电子顺磁共振波谱法测定Mn(II)中心。此外,(κ 5 - Ñ,Ñ,Ñ,Ñ,ñ - PyEt PDEA)Mn为确定为醛和酮的氢化硅烷化的有效预催化剂,表现出向上的周转频率2475分钟-1时溶剂下使用免费条件。这种优化可以分离出相应的醇,在两种情况下,还可以分离出部分反应的甲硅烷基醚PhSiH(OR)2 [R = Cy和CH(Me)(n Bu)]。对于(κ观察到的醛氢化硅烷化活性5 - ñ,N,N,N,N