Pd-Catalyzed Direct C7 Trifluoromethylation of Indolines with Umemoto’s Reagent
Qinglang Song, Lin Zhang, Bin Wang, Ziren Chen, Weiwei Jin, Yu Xia, Shaofeng Wu, Chenjiang Liu, Yonghong Zhang
Abstract
An efficient palladium-catalyzed region-selective C7-trifluoromethylation of indolines using commercially available Umemoto’s reagent was reported. The reaction utilizing Umemoto’s reagent as CF 3 radical precursor, pyrimidine as a removable directing group, Pd(II) as a catalyst, and Cu(II) as an oxidant furnished the required products with excellent regioselectivities and good yields. The present strategy has good region-selectivity, broad substrate scope, and scale-up application. Additionally, the present method was underlined by the direct C-1 trifluoromethylation of carbazoles. Furthermore, C7 trifluoromethylated indole can also be easily obtained via Pd-catalyzed direct C-7 trifluoromethylation/oxidation/deprotection sequential reactions.