CCNU-uOttawa Joint Research Centre, Key Laboratory of Pesticides & Chemical Biology Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei, China.
State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, China.
Nat Commun. 2021 Mar 22;12(1):1815. doi: 10.1038/s41467-021-22127-x.
The intermolecular three-component alkene vicinal dicarbofunctionalization (DCF) reaction allows installation of two different carbon fragments. Despite extensive investigation into its ionic chemistry, the enantioseletive radical-mediated versions of DCF reactions remain largely unexplored. Herein, we report an intermolecular, enantioselective three-component radical vicinal dicarbofunctionalization reaction of olefins enabled by merger of radical addition and cross-coupling using photoredox and copper dual catalysis. Key to the success of this protocol relies on chemoselective addition of acyl and cyanoalkyl radicals, generated in situ from the redox-active oxime esters by a photocatalytic N-centered iminyl radical-triggered C-C bond cleavage event, onto the alkenes to form new carbon radicals. Single electron metalation of such newly formed carbon radicals to TMSCN-derived L1Cu(II)(CN) complex leads to asymmetric cross-coupling. This three-component process proceeds under mild conditions, and tolerates a diverse range of functionalities and synthetic handles, leading to valuable optically active β-cyano ketones and alkyldinitriles, respectively, in a highly enantioselective manner (>60 examples, up to 97% ee).
分子间的三组分烯烃邻位双官能化(DCF)反应允许安装两个不同的碳片段。尽管对其离子化学进行了广泛的研究,但选择性自由基介导的 DCF 反应的对映选择性版本在很大程度上仍未得到探索。在此,我们报告了一种通过光氧化还原和铜双催化融合实现的分子间、对映选择性的三组分自由基邻位双官能化反应,该反应能够实现烯烃的反应。该反应成功的关键在于通过光催化 N 中心亚氨基自由基引发的 C-C 键断裂事件,从氧化还原活性肟酯原位生成酰基和氰烷基自由基,然后选择性地加成到烯烃上,形成新的碳自由基。新形成的碳自由基的单电子金属化作用导致与 TMSCN 衍生的 L1Cu(II)(CN)配合物的不对称交叉偶联。该三组分反应在温和条件下进行,并能耐受多种官能团和合成处理,以高度对映选择性的方式(>60 个实例,最高可达 97%ee)分别得到有价值的光学活性β-氰基酮和烷基二腈。