Du Hai-Wu, Du Yi-Dan, Zeng Xian-Wang, Shu Wei
Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, P. R. China.
State Key Laboratory of Elemento-Organic Chemistry, Nankai University, 300071, Tianjin, P. R. China.
Angew Chem Int Ed Engl. 2023 Sep 18;62(38):e202308732. doi: 10.1002/anie.202308732. Epub 2023 Aug 10.
Aliphatic trifluoromethyl ketones are a type of unique fluorine-containing subunit which play a significant role in altering the physical and biological properties of molecules. Catalytic methods to provide direct access to aliphatic trifluoromethyl ketones are highly desirable yet remain underdeveloped, partially owing to the high reactivity and instability of trifluoroacetyl radical. Herein, we report a photocatalytic synthesis of trifluoromethyl ketones from alkyl bromides with trifluoroacetic anhydride. The reaction features dual visible-light and halogen-atom-transfer catalysis, followed by an enabling radical-radical cross-coupling of an alkyl radical with a stabilized trifluoromethyl radical. The reaction provides straightforward access to aliphatic trifluoromethyl ketones from readily available and cost-effective alkyl halides and trifluoroacetic anhydride (TFAA).
脂肪族三氟甲基酮是一类独特的含氟亚基，在改变分子的物理和生物学性质方面发挥着重要作用。直接合成脂肪族三氟甲基酮的催化方法备受期待，但仍未得到充分发展，部分原因是三氟乙酰基自由基的高反应性和不稳定性。在此，我们报道了一种以溴代烷烃和三氟乙酸酐为原料光催化合成三氟甲基酮的方法。该反应具有可见光和卤素原子转移双重催化作用，随后是烷基自由基与稳定的三氟甲基自由基之间的自由基-自由基交叉偶联反应。该反应可从容易获得且成本效益高的卤代烷烃和三氟乙酸酐（TFAA）直接合成脂肪族三氟甲基酮。
