Direct electrophilic and radical isoperfluoropropylation with i-C3F7-Iodine(III) reagent (PFPI reagent)

Abstract

The isoperfluoropropyl group (i-C3F7) is an emerging motif in pharmaceuticals, agrichemicals and functional materials. However, isoperfluoropropylated compounds remain largely underexplored, presumably due to the lack of efficient access to these compounds. Herein, we disclose the practical and efficient isoperfluoropropylation of aromatic C-H bonds through the invention of a hypervalent-iodine-based reagent-PFPI reagent, that proceeds via a Ag-X coupling process. The activation of the PFPI reagent without any catalysts or additives was demonstrated in the synthesis of isoperfluoropropylated electron-rich heterocycles, while its activity under photoredox catalysis was shown in the synthesis of isoperfluoropropylated non-activated arenes. Detailed mechanistic experiments and DFT calculations revealed a SET-induced concerted mechanistic pathway in the photoredox reactions. In addition, the unique conformation of i-C3F7 in products, that involved intramolecular hydrogen bond was investigated by X-ray single-crystal diffraction and variable-temperature NMR experiments.

Light promoted metal-free regio- and stereoselective isoperfluoropropylation of unactivated alkenes with an i-C3F7-iodine(iii) reagent

“…8 In particular, the development of hypervalent aryl-λ 3 -iodane based trifluoromethylating reagents by Togni and co-workers has extremely expanded the scope of direct electrophilic trifluoromethylation methods. 2 a As a continuation of our interest in both fluorine chemistry and hypervalent iodine chemistry, 9 we envisaged that the merger of the i-C 3 F 7 group with a hypervalent aryl-λ 3 -iodane scaffold (PFPI reagent) would provide a platform for the development of novel isoperfluoropropylation methods. In 2011, Buchwald and Wang reported their efforts in developing a catalytic trifluoromethylation of terminal olefins using the Togni reagent, in which Cu( i ) plays a role in activating the Togni reagent (Fig.…”