Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie Pvt., Ottawa, Ontario, K1N 6N5, Canada.
Angew Chem Int Ed Engl. 2021 Jul 5;60(28):15598-15605. doi: 10.1002/anie.202104595. Epub 2021 Jun 7.
The direct conversion of carboxylic acids into disulfides is described. The approach employs oxidative photocatalysis for base-promoted decarboxylation of the substrate, which yields an alkyl radical that reacts with a trisulfide dioxide through homolytic substitution. The trisulfide dioxides are easily prepared by a newly described approach. 1°, 2°, and 3° carboxylic acids with varied substitution are good substrates, including amino acids and substrates with highly activated C-H bonds. Trisulfide dioxides are also used to achieve the γ-C(sp )-H disulfuration of amides through a radical relay sequence. In both reactions, the sulfonyl radical that results from substitution propagates the reaction. Factors governing the selectivity of substitution at S2 versus S3 of the trisulfide dioxides have been explored.
描述了一种将羧酸直接转化为二硫化物的方法。该方法采用氧化光催化作用，通过碱促进底物脱羧，生成烷基自由基，然后该自由基与三磺酰基二氧通过均裂取代反应。三磺酰基二氧可通过新描述的方法轻松制备。1°、2°和 3°羧酸具有不同取代基，是很好的底物，包括氨基酸和具有高活性 C-H 键的底物。三磺酰基二氧还可用于通过自由基接力序列实现酰胺的γ-C(sp3)-H 二硫化。在这两种反应中，取代产生的砜基自由基都可推动反应进行。已经探索了控制三磺酰基二氧中 S2 和 S3 取代选择性的因素。
