Oxidant-Assisted Sulfonylation/Cyclization Cascade Synthesis of Alkylsulfonylated Oxindoles via the Insertion of SO<sub>2</sub>
作者:Long-Jin Zhong、Hui Chen、Xuan Shang、Bi-Quan Xiong、Ke-Wen Tang、Yu Liu
DOI:10.1021/acs.joc.3c02860
日期:2024.4.19
An oxidant-assisted tandem sulfonylation/cyclization of electron-deficient alkenes with 4-alkyl-substituted Hantzsch esters and Na2S2O5 for the preparation of 3-alkylsulfonylated oxindoles under mild conditions in the absence of a photocatalyst and transition metal catalyst is established. The mechanism studies show that the alkyl radicals, which come from the cleavage of the C–C bond in 4-substituted
缺电子烯烃与4-烷基取代的Hantzsch酯和Na 2 S 2 O 5的氧化剂辅助串联磺酰化/环化反应,在温和条件下,在没有光催化剂和过渡金属催化剂的情况下制备3-烷基磺酰化羟吲哚的方法是已确立的。机理研究表明,在氧化剂条件下,4-取代Hantzsch酯中C-C键断裂产生的烷基自由基,随后经历二氧化硫的原位插入,生成关键的烷基磺酰自由基中间体。这种三组分反应为构建烷基磺酰化羟吲哚提供了有效且简便的路线,并避免使用剧毒的烷基磺酰氯或烷基磺酰肼作为烷基磺酰基源。