Synthesis of 5-Trifluoromethyl-Substituted (Z)-N,N-Dimethyl-N′-(pyrazin-2-yl)formimidamides from 2-Aminopyrazines, LiI/Selectfluor, FSO2CF2CO2Me and DMF under Cu Catalysis
作者:Jiao Hu、Shengyu Li、Sheng-Cai Zheng、Xiaoming Zhao、Xiaolin Wang
DOI:10.1055/s-0037-1610792
日期:2022.5
amides via the iodination of 2-aminopyrazines with Selectfluor/LiI followed by a domino trifluoromethylation with FSO2CF2CO2Me and a condensation with DMF in the presence of CuI is realized under mild conditions. This three-step method offers CF3-substituted (Z)-N,N-dimethyl-N′-(pyrazin-2-yl)formimidamides in yields of 55–70% and with high regioselectivities. LiI serves as an iodine source, whilst
用 Selectfluor/LiI 碘化 2-氨基吡嗪,然后用 FSO 2 CF 2进行多米诺三氟甲基化,合成 5-三氟甲基取代的 ( Z )- N , N -二甲基- N '-(pyrazin-2-yl)formimidamides在温和条件下,在 CuI 存在下实现CO 2 Me 和与 DMF 的缩合。这种三步法提供了 CF 3 -取代的 ( Z )- N , N -二甲基- N'-(pyrazin-2-yl)formimidamides 的产率为 55-70% 并具有高区域选择性。LiI 用作碘源,而 DMF 用作溶剂和缩合试剂。这些三氟甲基化反应的区域选择性很大程度上取决于 2-氨基吡嗪上的取代基模式。还讨论了这种方法的可能机制。