Abstract
<jats:p>Skeletal editing is gaining increasing attention in synthetic chemistry as it enables precise atom-level modifications to reframe molecular structures. However, the single formal carbon-fluorine insertion, which will give access to synthetically challenging or unprecedented fluorinated compounds, remains an underexplored strategy. In this work, the single carbon-fluorine insertion to readily available quinolinium salts is presented. An in situ formed sulfurylide based surrogate of inaccessible diazofluoromethane is used as a fluorocarbyne synthon, which undergoes ring expansion or ring expansion/ring contraction by either thermal or photochemical conditions to build fluorinated benzo[b]azepines and their valence tautomers dihydrocyclobuta[b]indoles via a divergent one-pot procedure. The setup proceeds smoothly for a wide variety of substrates, and the synthetic utility of this method was demonstrated by easy upscaling, as well as by blocking the tautomerism upon hydrogenation. Thus, this strategy not only avoids the use of hazardous diazomethane reagents and expands the organofluorine chemical space, but also offers an easy, modular protocol towards fluorinated heterocycles for potential lead structure identification.</jats:p>