Substrate scope of benzamides^a,b.

^aReactions were carried out by using 1a (0.1 mmol), 2 (0.3 mmol), Co(OAc)₂·4H₂O (0.02 mmol), Mn(OAc)₂ (0.2 mmol), CsF (0.12 mmol), TFE (1.0 ml), 100 °C, O₂, 24 h.

^bIsolated yield.

^cCsF (0.3 mmol).

^dCsF (0.3 mmol), 120 °C.