Cationic Nickel(II)-Catalyzed Hydrosilylation of Alkenes: Role of P, N-Type Ligand Scaffold on Selectivity and Reactivity
作者:Istiak Hossain、Joseph A. R. Schmidt
DOI:10.1021/acs.organomet.0c00551
日期:2020.9.28
Seven structurally similar cationic nickel(II)–alkyl complexes were synthesized by using a series of P, N ligands, and their reactivity was explored in the hydrosilylation of alkenes. More electron-rich phosphines enhanced the overall reactivity of the transformation; in contrast, groups on the imine donor had little impact. Overall, these catalysts displayed reactivity and selectivity that was previously
使用一系列P,N配体合成了七个结构相似的阳离子镍(II)-烷基络合物,并在烯烃的氢硅烷化中探索了它们的反应性。更多的富电子膦提高了转化的整体反应性;相反,亚胺供体上的组几乎没有影响。总体而言,这些催化剂显示出在镍催化的氢化硅烷化中以前未知或非常罕见的反应性和选择性。在与Ph 2 SiH 2的反应中,1,2-二取代的乙烯基芳烃显示出对硅烷加成的完全苄基选择性,而对1,1-二取代的烯烃则观察到末端选择性。相关的PhSiH 3导致仅对单个取代的乙烯基芳烃进行马尔可夫尼科夫选择性,而未观察到竞争的双加成。机理研究支持以下假设:Ni-H在此催化氢硅烷化反应中充当活性物质,这反过来也显示了硅烷再分布反应的催化能力,特别是对于空间不受阻的硅烷。