Photocatalytic Intramolecular C–H Amination Using N‑Oxyureas as Nitrene Precursors

Nitrenes are remarkable high-energy chemical species that enable direct C–N bond formation, typically via controlled reactions of metal-stabilized nitrenes. Here, in contrast, the combined use of photocatalysis with careful engineering of the precursor enabled C–H amination forming imidazolidinones and related nitrogen heterocycles from readily accessible hydroxylamine precursors. Preliminary mechanistic results are consistent with the formation of free carbamoyl triplet nitrenes as reactive intermediates.

氮宾（nitrenes）是一类具有极高能量的化学物种，通常可通过金属稳定化氮宾的可控反应实现直接碳-氮键的构建。与之不同的是，本工作通过将光催化与前驱体的精准工程化设计相结合，以易于获取的羟胺前驱体为原料，通过碳氢键胺化反应合成了咪唑烷酮及相关氮杂环化合物。初步机理研究结果与游离氨基甲酰三重态氮宾作为活性中间体的生成过程相符。