Have you tried water, ethanol, or a mixture of the two?

DMSO or dimethyl formamide?

Ethanol and water for this substrate forms acetals and hydrates respectively and thus is not preferred. I will try DMF.

HFIP (hexafluoro isopropanol) might be a good choice

I am totally agreed with Joaquin Barjau, HFIP or triflouroethanol should be better options than other solvents.

You can use acetonitrile methanol mixture it works so well. Also from experience you can first dissolve at low temperatures and then increase to ambient teperature. Also water works well as co solvent if its for reactions.

My recommendation is that you make the anion of the ketone in THF, then added the SFt and finally add a few drops of DMF. I think that the reaction should workl, although the SF will not dissolve completely.

THF is the standard solvent for fluorination of this sort. You can also try other fluorinating agents as Selectfluor tends to give the elimination product as well, depending on the structure of your ketone (benzophenone will give you the fluorostyrene as a a major side product).

You can give a shot at XtalFluor-M or -E, which is a more stable form of deoxofluor and DAST (contains much less acid). Those reactions are preformed in DCM and were shown to favor difluorination versus monofluorination/elimination as compared to deoxofluor:

http://pubs.acs.org/doi/abs/10.1021/ol902039q

http://pubs.acs.org/doi/abs/10.1021/jo100504x?journalCode=joceah&quickLinkVolume=75&quickLinkPage=3401&volume=75

Joseph,

The Selectfluor contains two positive charges. I think DMSO or DMF will be a good choice.

Ionic liquids may be used to your advantage.

Ref: Chemical Communications., 2002, 488

Arkivoc 202, xi 249-255

I think, You can use Toluene as solvent for your project. It is better solvent than acetonitrile. I have used in my project, i got positive result. You can Try

Yes i agree with Afaf, THF is the best solvent

Ref: US20060100164; WO2009055557

THF is not protic

Trifluorotoluene