Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
Institute of Organic and Polymeric Materials, National Taipei University of Technology , 1, Sec. 3, Chung-Hsiao E. Road, Taipei 106, Taiwan.
Org Lett. 2017 Sep 1;19(17):4552-4555. doi: 10.1021/acs.orglett.7b02147. Epub 2017 Aug 15.
A regioselective C-H sulfanylation of aryl sulfoxides with alkyl aryl sulfides in the presence of acid anhydride was developed, which resulted in the formation of 1,4-disulfanylarenes after dealkylation of initially formed sulfonium salts. The reaction began with Pummerer-type activation of aryl sulfoxides followed by nucleophilic attack of alkyl aryl sulfides. The nucleophilic attack occurred exclusively at the para positions, or at specific positions in case the para position was not available, under perfect control by the dominating sulfoxide directors regardless of any other substituents. The initially formed aryl sulfonium salts were isolable and usefully served as aryl halide surrogates for palladium-catalyzed arylation with sodium tetraarylborates.
在酸酐存在的条件下，芳基砜与烷基芳基硫醚发生区域选择性 C-H 硫代反应，最初形成的锍盐脱烷基后生成 1,4-二硫芳烯。反应首先通过 Pummerer 型芳基砜的活化，然后是烷基芳基硫醚的亲核进攻。亲核进攻仅在对位发生，或者在对位不可用时在特定位置发生，在主导的砜基的完美控制下，无论其他取代基如何，都能得到很好的控制。最初形成的芳基锍盐是可分离的，并可作为芳基卤化物的替代物，用于钯催化与四芳基硼酸钠的芳基化反应。
