Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
Shenzhen Bay Laboratory, Shenzhen, 518055, China.
J Am Chem Soc. 2021 Nov 17;143(45):19091-19098. doi: 10.1021/jacs.1c08382. Epub 2021 Nov 4.
The enantioselective construction of quaternary carbon centers is a marked challenge in asymmetric catalysis research. It is extremely difficult when a chiral catalyst can not distinguish the facial selectivity of the substrate through bond interactions. Here we realized an enantioselective Michael reaction of silyl ketene imines to 1-acrylpyrazoles using a chiral -dioxide-Co(II) complex. The protocol is highly efficient for the construction of nitrile-, aryl-, and dialkyl-bearing carbon centers and has been successful applied in the divergent synthesis of pharmaceuticals and natural products. The through-space dispersion interactions between unbound silyl ketene imines and the 1-acrylpyrazole-bonded catalyst play a key role in facilitating the reactivity and the enantioselectivity of this process.
手性二氧化硅-钴（II）配合物促进的硅烯酮亚胺的对映选择性迈克尔加成反应
手性二氧化硅-钴（II）配合物促进的硅烯酮亚胺的对映选择性迈克尔加成反应
在手性催化中，当手性催化剂不能通过键相互作用区分底物的面选择性时，季碳原子的对映选择性构建是一个显著的挑战。在这里，我们使用手性二氧化硅-钴（II）配合物实现了硅烯酮亚胺与 1-丙烯基吡唑的对映选择性迈克尔加成反应。该方案对于构建含腈基、芳基和二烷基的碳中心非常有效，并已成功应用于药物和天然产物的发散合成中。未结合的硅烯酮亚胺与与 1-丙烯基吡唑键合的催化剂之间的空间分散相互作用在促进该过程的反应性和对映选择性方面发挥了关键作用。
