Chemistry question:
Can acyl azides be prepared from carboxylic acids without activation of the carboxyl group (acyl chloride, anhydride, carbodiimide, active ester, etc.)? I’m preparing a precursor for Curtius rearrangement and hydrolysis to prepare the amine with one less C. (No other sensitive functional groups are present). Have you ever heard of cesium fluoride being used in this context? I know the best approach is to use DPPA, but interested in other options.