Acyl Azolium-Photoredox-Enabled Synthesis of β-Keto Sulfides.
Acyl Azolium-Photoredox-Enabled Synthesis of β-Keto Sulfides.
复制标题
酰基唑鎓光氧化还原合成β-酮硫化物。
DOI：
10.1021/acscatal.3c01558
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发表时间：
2023
期刊：
影响因子：
12.9
通讯作者：
Scheidt,KarlA
中科院分区：
文献类型：
--
作者：
Rourke,MichaelJ;Wang,CharlesT;Schull,CullenR;Scheidt,KarlA
α-杂原子官能化是有机合成中 C-C 键形成的关键策略，例如在亲电官能团（例如亚胺离子）上添加亲核试剂；氧碳鎓离子；及其硫类似物，硫鎓离子。我们设想通过硫化物的单电子氧化实现光氧化还原自由基普默勒型反应。在该氧化事件之后，α-去质子化将提供 α-硫代自由基，该自由基参与与唑鎓键合的羰基自由基的自由基-自由基偶联反应，从而在生成功能化添加剂 Pummerer 产品的过程中获得通常提出的自由基-自由基偶联的机械中间体。该系统为高度功能化的含硫产品提供了一种补充合成方法，包括对肽中的甲硫氨酸残基进行修饰，并呼吁对先前仅限于标准双电子过程的 C-C 键形成进行进一步探索。
α-Heteroatom functionalization is a key strategy for C–C bond formation in organic synthesis, as exemplified by the addition of a nucleophile to electrophilic functional groups, such as iminium ions; oxocarbenium ions; and their sulfur analogues, sulfenium ions. We envisioned a photoredox-enabled radical Pummerer-type reaction realized through the single-electron oxidation of a sulfide. Following this oxidative event, α-deprotonation would afford α-thio radicals that participate in radical–radical coupling reactions with azolium-bound ketyl radicals, thereby accessing a commonly proposed mechanistic intermediate of the radical–radical coupling en route to functionalized additive Pummerer products. This system provides a complementary synthetic approach to highly functionalized sulfurous products, including modification of methionine residues in peptides, and beckons further exploration in C–C bond formations previously limited in the standard two-electron process.