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

The synthesis of fluorinated isoquinoline\nderivatives\nholds significant\nvalue in organic synthesis and medicine. Research into the reaction\nmechanisms and possible pathways for synthesizing these compounds\nplays a crucial role in advancing the development and applications\nof isoquinoline derivatives. Using density functional theory methods,\nwe explored the reaction mechanism and potential pathways of the Rh(III)-catalyzed\ndefluorinative annulation of N-sulfonylarylamides with ethyl 2-diazo-3,3,3-trifluoropropanoates.\nTheoretical calculations indicate that the reaction initiates with\nthe formation of a metal carbene via C–H activation and denitrogenation,\nfollowed by migratory insertion. Subsequent steps involve metal-assisted\nβ-fluoride elimination and anion exchange. Finally, intramolecular\ncyclization, defluorination, and sulfonyl migration yield isoquinoline\nproducts.