Optimization of reaction conditions for C–H pentafluoroethylation using acid C₂F₅–Togni as a source^a,b.

Entry	Catalyst	Solvent, conditions	Yield [%]
1	1	DMSO, air	17
2	1	DMSO	97
3	1	DMSO, pyridine	95
4	1	MeCN	78
5	1	MeOH	58
6	NiCl2(glyme)	DMSO	0
7	NiBr2(glyme)	DMSO	0
8	AgF	DMSO	26
9c	AgF	DMSO	56
10c,d	AgF	DMSO	13
11	Ag(OSO2CF3)	DMSO	0
12	AgBr	DMSO	0
13c	AgBr	DMSO	0
14	None	DMSO	6*

^aThe reaction was performed under nitrogen unless indicated otherwise.

^bNMR yield was based on integration against α,α,α-trifluorotoluene as an internal standard.

^c100 equiv. of silver salt used.

^d Para-chloro-N-phenylpyrrole used as substrate (*) indicates the average yield of three reactions.