Selective 19F-labeling of functionalized carboxylic acids with difluoromethyl diazomethane (CF2HCHN2)
Chem. Eur. J. 2017, 23 (54), 13279-13283
Mykhailiuk P.; Kishko I.; kubyshkin V.; Budisa N.; Cossy J.
The incorporation of fluorinated moieties into organic structures is a particularly powerful approach for generating compounds with useful biological applications in industry, pharmacology, and agriculture. Here, the recently developed reagent—CF2HCHN2—selectively esterifies carboxyl groups on organic molecules in the presence of other polar functional groups. The reaction is remarkably simple, proceeding at room temperature in chloroform without addition of a catalyst. The procedure allows “last-step” incorporation of a fluorinated ester moiety into organic structures, including bioorganic molecules such as peptides and proteins. The fluorinated ester can subsequently function as a 19F-probe in biomolecules, thereby enabling molecular size determination by diffusion 19F NMR experiments.