Photoenzymatic Generation of Unstabilized Alkyl Radicals: An Asymmetric Reductive Cyclization
作者:Phillip D. Clayman、Todd K. Hyster
DOI:10.1021/jacs.0c07918
日期:2020.9.16
Flavin-dependent 'ene'-reductases (ERED) can generate stabilized alkyl radicals when irradiated with visible light, however, they are not known to form unstabilized radicals. Here, we report an enantioselective radical cyclization using alkyl iodides as precursors to unstabilized nucleophilic radicals. Evidence suggests this species is accessed by photoexcitation of a charge-transfer complex that forms between flavin
当用可见光照射时,黄素依赖性“烯”还原酶 (ERED) 可以产生稳定的烷基自由基,但是,不知道它们会形成不稳定的自由基。在这里,我们报告了使用烷基碘作为不稳定亲核自由基的前体的对映选择性自由基环化。有证据表明,该物种是通过光激发在黄素和蛋白质活性位点内的底物之间形成的电荷转移复合物而获得的。氢原子从黄素半醌到环化后形成的前手性自由基的立体选择性传递提供了跨各种底物的高水平的对映选择性。此外,我们发现氧化还原活性酯可用于代替烷基碘作为自由基前体。全面的,