From alchemy to precision skeletal editing.

Medieval alchemists dreamt of transmuting base metals, such as lead, into gold. Similarly, modern organic chemists dream of transforming one atom of a molecule into another atom without disturbing the original structure. Selectively converting a carbon atom of a carbocycle—a ring-shaped molecule containing only carbon—into a nitrogen atom results in the formation of a nitrogen heterocycle, which comprise more than 59% of small-molecule drugs approved by the US Food and Drug Administration (1). However, swapping a carbon atom with another atom is an extremely difficult task because this requires breaking stong C–C bonds. On pages 528 and 536 of this issue, Li et al. (2) and Zhang et al. (3), respectively, report strategies to transform carbocycles into nitrogen heterocycles. These approaches could diversify the library of pharmaceutically relevant molecules and contribute to drug discovery. [ABSTRACT FROM AUTHOR]