Sequentially snipping off fluorines It is often useful in pharmaceutical or agrochemical research to modify the properties of carbon compounds by appending one or more fluorine atoms. However, the methods used to prepare mono-, di-, or trifluorocarbon centers tend to differ from each other in inconvenient ways. Yu et al. developed a radical reaction that can successively remove one or two fluorine atoms from trifluoromethyl groups adjacent to amides or esters. The mechanism relies on a spin-center shift after attack at the carbonyl oxygen by a boryl radical. Science , this issue p. 1232