Pd-catalyzed Suzuki–Miyaura cross-coupling of [Ph 2 SR][OTf] with arylboronic acids
作者:Xiao-Yan Wang、Hai-Xia Song、Shi-Meng Wang、Jing Yang、Hua-Li Qin、Xin Jiang、Cheng-Pan Zhang
DOI:10.1016/j.tet.2016.10.018
日期:2016.11
The Pd-catalyzed Suzuki–Miyaura cross-coupling of alkyl- and fluoroalkyl(diphenyl)sulfonium triflates with arylboronic acids was compared. The fluorine substitution on the alkyl groups of [Ph2SR][OTf] had a big influence on the reaction. Perfluoroalkyl(diphenyl)sulfonium triflates (2b–d) were unsuccessful participants in the Pd-catalyzed phenylation of arylboronic acid under the standard conditions because
比较了Pd催化的三氟甲基磺酸烷基酯和氟代烷基(二苯基)ulf与芳基硼酸的Suzuki-Miyaura交叉偶联。[Ph 2 SR] [OTf]烷基上的氟取代对反应有很大影响。在标准条件下,全氟烷基(二苯基)ulf三氟甲磺酸酯(2b–d)未能成功地参与Pd催化的芳基硼酸的苯基化反应,因为长链全氟烷基具有很强的负电性,而是经S R fn键断裂。多氟烷基三苯二氟es(2f–h)与芳基硼酸反应,由于de盐的去质子化和β-F消除的趋势,以非常低的收率得到苯基化产物。最终,发现(2,2,2-三氟乙基)三氟甲磺酸二苯基s(2e),三氟甲磺酸甲基或乙基(二苯基)i(2i或2j)和三氟甲磺酸三苯基s(2m)是比其他测试过的苯基硫salts盐更有效的试剂钯催化的苯基化反应,在温和条件下可提供更高的所需产物收率。