Copper-Catalyzed Trifluoromethylation of Internal Olefinic CH Bonds: Efficient Routes to Trifluoromethylated Tetrasubstituted Olefins and N-Heterocycles
作者:Zhifeng Mao、Fei Huang、Haifeng Yu、Jiping Chen、Zhengkun Yu、Zhaoqing Xu
DOI:10.1002/chem.201305069
日期:2014.3.17
olefins has been a challenging task in organic synthesis. Efficient CuII‐catalyzed trifluoromethylation of internal olefins, that is, α‐oxoketene dithioacetals, has been achieved by using Cu(OH)2 as a catalyst and TMSCF3 as a trifluoromethylating reagent. The push–pull effect from the polarized olefin substrates facilitates the internal olefinic CH trifluoromethylation. Cyclic and acyclic dithioalkyl α‐oxoketene
内烯烃的官能化一直是有机合成中的一项艰巨任务。通过使用Cu(OH)2作为催化剂和TMSCF 3作为三氟甲基化试剂,实现了高效的Cu II催化的内烯烃三氟甲基化,即α-氧杂环丁烯二硫缩醛。极化烯烃底物的推挽效应促进了内部烯烃CH三氟甲基化。环状和无环二硫代烷基α-氧杂环丁烯缩醛用作底物,并且可以接受各种取代基。内烯烃CH键裂解不参与速率确定步骤,基于三氟甲基化反应的TEMPO猝灭实验,提出了一种涉及自由基的机理。所得CF 3烯烃的进一步衍生导致多官能化的四取代CF 3烯烃和三氟甲基化的N-杂环。