New Twist On Chiral Fluorination

Recent advances in organofluorine chemistry have made fluorinated compounds—widely sought as pharmaceuticals and agrochemicals—more readily available than ever before. One of the final frontiers is developing general methods for selectively making compounds with chiral C–F bonds. A European research team has now developed a chiral version of a popular fluorinating reagent that could help streamline such efforts (Angew. Chem. Int. Ed. 2013, DOI: 10.1002/anie.201304845). Véronique E. Gouverneur of Oxford University, Graham Sandford of Durham University, Peter R. Moore of AstraZeneca, and their coworkers were developing a tandem fluorination-cyclization process to make fluorinated tetracyclic compounds containing a quaternary C–F stereocenter. Such compounds could be used as intermediates for making fluorinated steroids, for example. Along the way, the researchers found that an efficient way to enantioselectively make the tetracyclic compounds was by using a chiral derivative of Selectfluor. They prepared the reagent by adding phenyl groups to Selectfluor’s framework.