Regioselective Single and Double Hydrophosphination and Hydrophosphinylation of Unactivated Alkynes
作者:Miriam M. I. Basiouny、Deborah A. Dollard、Joseph A. R. Schmidt
DOI:10.1021/acscatal.9b01538
日期:2019.8.2
A lanthanum-based N,N-dimethylbenzylamine complex was used as a precatalyst for both hydrophosphination and hydrophosphinylation of alkynes under mild conditions. In the case of hydrophosphination, the catalyst induced monoaddition with high regiospecificity, yielding only the anti-Markovnikov product, and stereoselectivity that could be controlled on the basis of the reaction conditions. Undertaking
基于镧的N,N-二甲基苄胺络合物用作在温和条件下炔烃的加氢磷酸化和加氢膦酰基化的预催化剂。在加氢磷酸化的情况下,该催化剂以高区域特异性诱导单加成,仅产生抗马尔科夫尼科夫产物和可根据反应条件控制的立体选择性。用过量的膦进行催化,以E异构体为主要产物。然而,使用过量的炔烃,Z异构体被分离为主要产物。对催化循环的简要研究表明,磷化镧活性催化剂的二聚体形式提供了Z异构体作为动力学产物,然后进行异构化以生成最终的E异构体。在氢次膦酰基化的情况下,化学选择性取决于所用炔烃的性质。末端炔烃仅产生双加成产物,而内部炔烃则成功分离出单加成产物和双加成产物。由于仅分离出抗马尔科夫尼科夫产物,氢次膦酰基化还显示出高的化学和区域选择性。内部炔烃的单氢次膦酰基化几乎只给出了E异构体,所有炔烃的两次氢次膦酰化导致了1,2-加成产物。