Mechanistic Studies on Rh(III)-Catalyzed Defluorinative Annulation of N‑Sulfonylarylamides with Ethyl 2‑Diazo-3,3,3-Trifluoropropanoates

The synthesis of fluorinated isoquinoline
derivatives
holds significant
value in organic synthesis and medicine. Research into the reaction
mechanisms and possible pathways for synthesizing these compounds
plays a crucial role in advancing the development and applications
of isoquinoline derivatives. Using density functional theory methods,
we explored the reaction mechanism and potential pathways of the Rh(III)-catalyzed
defluorinative annulation of N-sulfonylarylamides with ethyl 2-diazo-3,3,3-trifluoropropanoates.
Theoretical calculations indicate that the reaction initiates with
the formation of a metal carbene via C–H activation and denitrogenation,
followed by migratory insertion. Subsequent steps involve metal-assisted
β-fluoride elimination and anion exchange. Finally, intramolecular
cyclization, defluorination, and sulfonyl migration yield isoquinoline
products.