I’m not remotely surprised, nor am I particularly impressed by the methodology of this study. DCM remains popular because it’s cheap and has great properties as an organic solvent (not flammable, low polarity, low boiling point). Really the only thing that isn’t great about it is that it’s derived from petroleum and carries a shit load of chlorine.
Without strong incentives to move, like a regulatory tax, where’s the financial incentive to find greener alternatives in reactions where “do it in DCM” has been the canonical answer for a hundred years?
DCM is also about the only good solvent left that is also resistant to lewis acids. I think that some people were pushing for benzotrifluoride as a replacement, but it just straight up doesn’t work as well where i tried it
Tbf before “do it in DCM” was “do it in CCL4” or “do it in benzene”, DCM just works without nuking operator’s liver
Lots of these new green solvents are also annoyingly polar so perhaps they can be used as replacements of other polar solvents but not anything else. I’m not using cyrene, fuck that
TFA is used because it works and is shelf-stable. Replacements like HCl in ether or ethyl acetate are bitch to make and when these can be bought, they have to be refrigerated all the way. Straight up not worth the effort on small scale
They don’t have to ditch them; we just need to make energy cheap enough to properly recycle them.
