How to couple these molecules using isothiocyanate (–NCS)-amine (–NH2) coupling reaction?
Hi, I am trying to couple these two molecules. The first reaction I thought about was using a basic buffer like bicarbonate buffer. But I can't do this reaction in aqueous medium since the amine-containing molecule self assembles in water. The next reaction I thought about was using DMF with a base like DIPEA (to deprotonate the amines since many of them are probably in NH3+ form as they were isolated from a TFA-mediated deprotection reaction in the last step). But the NCS is most likely to get hydrolyzed in the presence of a base like DIPEA. The last option could be to use pure DMF without a base but I am worried if the amines are all in NH3+ state, they won't be nucleophilic enough to attack the NCS group. I just a few milligrams of the NCS-containing molecule so I can't set up multiple reactions and figure out a way via trial and error. I can perform two reactions at most. If it were you, which conditions would you try first? Or would you try something different from what I already mentioned? Tysm in advance!
