Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
J Am Chem Soc. 2016 Nov 9;138(44):14582-14585. doi: 10.1021/jacs.6b10278. Epub 2016 Nov 1.
We have developed metal-free regiocontrolled dehydrogenative C-H/C-H cross-coupling of aryl sulfoxides with phenols by means of trifluoroacetic anhydride. Because the reaction would proceed through an interrupted Pummerer reaction followed by sulfonium-tethered [3,3]-sigmatropic rearrangement, the C-H/C-H coupling takes place exclusively between the ortho positions of both substrates. Various functional groups including carbonyl, halo, siloxy, and even boryl moieties are compatible. The biaryl products naturally possess hydroxy and sulfanyl groups, which allows the products to be useful synthetic intermediates, as evidenced by the syntheses of π-expanded heteroarenes such as unprecedented 7,12-dioxa[8]helicene.
我们开发了一种通过三氟乙酸酐实现的无金属区域控制的芳基砜与酚的脱氢 C-H/C-H 交叉偶联反应。由于反应将通过中断的 Pummerer 反应进行，然后是磺酰基连接的[3,3]-σ重排，因此 C-H/C-H 偶联仅在两个底物的邻位之间发生。各种官能团，包括羰基、卤代、硅氧基，甚至硼基，都兼容。联芳产物自然含有羟基和硫基，这使得产物成为有用的合成中间体，这可以从合成π扩展杂芳烃如前所未有的 7,12-二氧杂[8]螺环为例得到证明。
