在 rt–100 °C 的 K 2 CO 3作用下,杂芳基卤化物 (Cl, Br) 和硫醇之间的亲核芳香取代 (S N Ar) 在 DMAc 中顺利进行。对于大多数缺电子杂芳烃,反应的发生无需引入额外的吸电子基团。对于富电子杂芳烃,需要额外的吸电子基团(例如简单的酯基、酮基、氰基和硝基)以确保反应完成。杂芳基卤化物的反应性趋势高度依赖于杂芳烃的电子性质和卤素的方向。除了硫醇之外,一些官能化的硫脲和硫代酰胺也与这些条件相容,以良好的产率提供相应的杂芳基硫醚。
HFIP Promoted Low-Temperature S<sub>N</sub>Ar of Chloroheteroarenes Using Thiols and Amines
作者:Yuvraj B. Bhujabal、Kamlesh S. Vadagaonkar、Aniket Gholap、Yogesh S. Sanghvi、Rambabu Dandela、Anant R. Kapdi
DOI:10.1021/acs.joc.9b02371
日期:2019.12.6
A highly efficient and an unprecedented hexafluoro-2-propanol, promoting low-temperature aromatic nucleophilic substitutions of chloroheteroarenes, has been performed using thiols and (secondary) amines under base free and metal-free conditions. The developed protocol also provides excellent regio-control for the selective functionalization of dichloroheteroarenes, while the utility of the protocol was demonstrated by the modification of a commercially available drug ceritinib.