Jia Zongbin, Cheng Liang, Zhang Long, Luo Sanzhong
Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing, 100084, China.
Nat Commun. 2024 May 14;15(1):4044. doi: 10.1038/s41467-024-48350-w.
The direct alkenylation with simple alkenes stands out as the most ideal yet challenging strategy for obtaining high-valued desaturated alkanes. Here we present a direct asymmetric dehydrogenative α-C(sp)-H alkenylation of carbonyls based on synergistic photoredox-cobalt-chiral primary amine catalysis under visible light. The ternary catalytic system enables the direct coupling of β-keto-carbonyls and alkenes through a cooperative radical addition-dehydrogenation process involving a chiral α-imino radical and Co(II)-metalloradical intermediate. A catalytic H-transfer process involving nitrobenzene is engaged to quench in situ generated cobalt hydride species, ensuring a chemoselective alkenylation in good yields and high enantioselectivities.
用简单烯烃进行直接烯基化是获得高价值不饱和烷烃最理想但也最具挑战性的策略。在此，我们报道了一种基于可见光下协同光氧化还原-钴-手性伯胺催化的羰基化合物直接不对称脱氢α-C(sp)-H烯基化反应。该三元催化体系通过涉及手性α-亚氨基自由基和Co(II)-金属自由基中间体的协同自由基加成-脱氢过程，实现了β-酮羰基化合物与烯烃的直接偶联。利用涉及硝基苯的催化氢转移过程原位淬灭生成的氢化钴物种，确保了化学选择性烯基化反应具有良好的产率和高对映选择性。
