Radicals break C–F bonds one at a time

Abstract

Scientists want to be able to easily add fluorines to pharmaceuticals and agrochemicals because F-containing groups can help the molecules slip through cell membranes to where they are needed. Researchers now report that they can better control the synthesis of such mono- and difluorinated molecules, making these important classes of compounds more accessible to medicinal and agricultural chemists. ( Science , 2021, DOI: 10.1126/science.abg0781 ). Trifluoromethyl compounds are often fluorinating agents of choice because they are inexpensive and readily available. However, past attempts to efficiently swap out just one or two of the F atoms to make mono- and difluorinated compounds with other functional groups have typically failed. Once the first C–F bond is broken, the other two get weaker. As a result, when chemists try to switch out one or two F atoms, they tend to remove all three. In the new work, Yi-Feng Wang and coworkers at the