Divergent and Synergistic Photocatalysis: Hydro- and Oxoalkylation of Vinyl Arenes for the Stereoselective Synthesis of Cyclopentanols via a Formal [4+1]-Annulation of 1,3-Dicarbonyls
作者:Narenderreddy Katta、Quan-Qing Zhao、Tirtha Mandal、Oliver Reiser
DOI:10.1021/acscatal.2c04736
日期:2022.11.18
are initiated through the formation of polarity-reversed C-centered-radical intermediates at the active methylene center of 1,3-dicarbonyls via direct photocatalytic C–H bond transformations. The oxoalkylation of alkenes is achieved under aerobic conditions via a Cu(II)-photomediated rebound mechanism, while the corresponding hydroalkylation becomes possible under a nitrogen atmosphere by the combination
描述了 1,3-二羰基的可控发散反应性,这使得乙烯基芳烃的有效加氢和氧代烷基化成为可能。两种反应途径都是通过极性反转C的形成启动的通过直接光催化 C-H 键转换在 1,3-二羰基的活性亚甲基中心生成中心自由基中间体。烯烃的氧代烷基化在有氧条件下通过 Cu(II)-光介导的回弹机制实现,而相应的加氢烷基化在氮气气氛下通过 4CzIPN 和 Brønsted 碱的组合成为可能。这些不同方案的广度在药物和天然产物的后期修饰以及将产物转化为各种杂环化合物(如吡啶、吡咯或呋喃)中得到证明。此外,这两种催化模式可以协同组合,在正式的[4+1]-环化过程中立体选择性构建环戊醇衍生物。