Mazzarella Daniele, Qi Chun, Vanzella Michael, Sartorel Andrea, Pelosi Giorgio, Dell'Amico Luca
Department of Chemical Sciences, University of Padova, Via Francesco Marzolo 1, 35131, Padova, Italy.
Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17, 43124, Parma, Italy.
Angew Chem Int Ed Engl. 2024 Jun 17;63(25):e202401361. doi: 10.1002/anie.202401361. Epub 2024 May 14.
Aminocatalysis is a well-established tool that enables the production of enantioenriched compounds under mild conditions. Its versatility is underscored by its seamless integration with various synthetic approaches. While the combination of aminocatalysis with metal catalysis, photochemistry, and stoichiometric oxidants has been extensively explored, its synergy with electrochemical activation remains largely unexplored. Herein, we present the successful merger of electrochemistry and aminocatalysis to perform SOMO-type transformations, expanding the toolkit for asymmetric electrochemical synthesis. The methodology harnesses electricity to drive the oxidation of catalytically generated enamines, which ultimately partake in enantioselective radical processes, leading to α-alkylated aldehydes. Crucially, mechanistic studies highlight how this electrochemical strategy is enabled by the use of a redox shuttle, 4,4'-dimethoxybiphenyl, to prevent catalyst degradation and furnishing the coveted compounds in good yield and high enantioselectivity.
氨基催化是一种成熟的工具,能够在温和条件下生产对映体富集的化合物。它与各种合成方法的无缝结合突出了其多功能性。虽然氨基催化与金属催化、光化学和化学计量氧化剂的组合已得到广泛探索,但其与电化学活化的协同作用在很大程度上仍未被探索。在此,我们展示了电化学与氨基催化的成功结合,以进行单占据分子轨道(SOMO)型转化,扩展了不对称电化学合成的工具包。该方法利用电能驱动催化生成的烯胺的氧化,烯胺最终参与对映选择性自由基过程,生成α-烷基化醛。至关重要的是,机理研究突出了如何通过使用氧化还原穿梭剂4,4'-二甲氧基联苯来实现这种电化学策略,以防止催化剂降解,并以良好的产率和高对映选择性提供所需的化合物。