I dont know, as a wild thought, Will any LLE solvent work.
I mean where partition coeff for your aldehyde & iodine are diff.
See, every research has some commercial part attached to it.
So we have to see practical & economical solutions.
I am not aware of any such solvent right now, as I am not a chemist,
but getting it reacted with any compund such as sodium thio, carbonate, etc
doesn't have any commercial sense.
Thats why still lot of research is going on for Acetylation of Aromatics.
I know one process where solid catalyst is used which is re-usable without any
significant loss of reactivity, BUT yet to be tested.