Scaffold hopping by net photochemical carbon deletion of azaarenes
Jisoo Woo, Alec H. Christian, Samantha A. Burgess, Yuan Jiang, Umar Faruk Mansoor, Mark D. Levin
Abstract
Discovery chemists routinely identify purpose-tailored molecules through an iterative structural optimization approach, but the preparation of each successive candidate in a compound series can rarely be conducted in a manner matching their thought process. This is because many of the necessary chemical transformations required to modify compound cores in a straightforward fashion are not applicable in complex contexts. We report a method that addresses one facet of this problem by allowing chemists to hop directly between chemically distinct heteroaromatic scaffolds. Specifically, we show that selective photolysis of quinoline N -oxides with 390-nanometer light followed by acid-promoted rearrangement affords N -acylindoles while showing broad compatibility with medicinally relevant functionality. Applications to late-stage skeletal modification of compounds of pharmaceutical interest and more complex transformations involving serial single-atom changes are demonstrated.