57646-27-2Relevant academic research and scientific papers
The merger of decatungstate and copper catalysis to enable aliphatic C(sp 3)–H trifluoromethylation
Sarver, Patrick J.,Bacauanu, Vlad,Schultz, Danielle M.,DiRocco, Daniel A.,Lam, Yu-hong,Sherer, Edward C.,MacMillan, David W. C.
, p. 459 - 467 (2020/03/23)
The introduction of a trifluoromethyl (CF3) group can dramatically improve a compound’s biological properties. Despite the well-established importance of trifluoromethylated compounds, general methods for the trifluoromethylation of alkyl C–H bonds remain elusive. Here we report the development of a dual-catalytic C(sp3)–H trifluoromethylation through the merger of light-driven, decatungstate-catalysed hydrogen atom transfer and copper catalysis. This metallaphotoredox methodology enables the direct conversion of both strong aliphatic and benzylic C–H bonds into the corresponding C(sp3)–CF3 products in a single step using a bench-stable, commercially available trifluoromethylation reagent. The reaction requires only a single equivalent of substrate and proceeds with excellent selectivity for positions distal to unprotected amines. To demonstrate the utility of this new methodology for late-stage functionalization, we have directly derivatized a broad range of approved drugs and natural products to generate valuable trifluoromethylated analogues. Preliminary mechanistic experiments reveal that a ‘Cu–CF3’ species is formed during this process and the critical C(sp3)–CF3 bond-forming step involves the copper catalyst. [Figure not available: see fulltext.].
Mild and efficient palladium-catalyzed direct trifluoroethylation of aromatic systems by C-H activation
T?th, Balázs L.,Kovács, Szabolcs,Sályi, Gerg?,Novák, Zoltán
, p. 1988 - 1992 (2016/02/18)
The introduction of trifluoroalkyl groups into aromatic molecules is an important transformation in the field of organic and medicinal chemistry. However, the direct installation of fluoroalkyl groups onto aromatic molecules still represents a challenging and highly demanding synthetic task. Herein, a simple trifluoroethylation process that relies on the palladium-catalyzed C-H activation of aromatic compounds is described. With the utilization of a highly active trifluoroethyl(mesityl)iodonium salt, the developed catalytic method enables the first highly efficient and selective trifluoroethylation of aromatic compounds. The robust catalytic procedure provides the desired products in up to 95 % yield at 25 °C in 1.5 to 3 hours and tolerates a broad range of functional groups. The utilization of hypervalent reagents opens new synthetic possibilities for direct alkylations and fluoroalkylations in the field of transition-metal-catalyzed C-H activation.
