Liu Xiaojuan, Wen Qingqing, Xiang Li, Leng Xuebing, Chen Yaofeng
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China.
Chongqing Key Laboratory of Green Synthesis and Applications, College of Chemistry, Chongqing Normal University, Chongqing, 401331, P. R. China.
Chemistry. 2020 Apr 24;26(24):5494-5499. doi: 10.1002/chem.202000342. Epub 2020 Apr 15.
The synthesis and catalytic applications of trivalent rare-earth metal alkyl complexes have been well developed, but the chemistry of divalent rare-earth metal alkyl complexes lagged much behind. Herein, we report the synthesis, structure, and catalytic applications of a samarium(II) monoalkyl complex supported by a β-diketiminato-based tetradentate ligand, [LSmCH(SiMe ) ] (L=[MeC(NDipp)CHC(Me)NCH CH N(Me)CH CH NMe ] , Dipp=2,6-(iPr) C H ). This complex is synthesized by the salt metathesis reaction of samarium iodide [LSm(μ-I)] and KCH(SiMe ) in 63 % yield. Its structure is characterized by single-crystal X-ray diffraction, showing a distorted square-pyramid coordination geometry. This samarium(II) monoalkyl complex exhibits high catalytic activity in the hydrosilylation of aryl and methyl-substituted unsymmetrical internal alkynes with secondary hydrosilanes, selectively providing the α-(E) products in high yields.
三价稀土金属烷基配合物的合成及其催化应用已得到充分发展，但二价稀土金属烷基配合物的化学研究却远远落后。在此，我们报道了一种由基于β-二酮亚胺的四齿配体支撑的钐（II）单烷基配合物[LSmCH(SiMe ) ]（L = [MeC(NDipp)CHC(Me)NCH CH N(Me)CH CH NMe ] ，Dipp = 2,6-(iPr) C H ）的合成、结构及其催化应用。该配合物通过碘化钐[LSm(μ-I)]与KCH(SiMe ) 的盐复分解反应合成，产率为63%。其结构通过单晶X射线衍射表征，显示出扭曲的四方锥配位几何结构。这种钐（II）单烷基配合物在芳基和甲基取代的不对称内炔与仲硅烷的硅氢化反应中表现出高催化活性，能以高产率选择性地提供α-(E)产物。
