The SNAr reaction proved amenable to the preparation of a series of analogous dibenzodiazepinones (Figure ). Peripheral ring substitution with chloro-and aryl-substituents was well tolerated and afforded products 3b and 3e in high yield and selectivity (83%, 94:6 er and 95%, 89:11 er, respectively). On the other hand, replacing the methyl blocking group for a chlorine atom (R 4 = Cl, 3c) retained most of the selectivity, but caused an important reduction of conversion (and isolated yield), presumably due to the electron-withdrawing nature of the chlorine substituent (11%, 87:13 er). Notably, replacement of the 2-nitro group of 3a for a 4-nitro group was well tolerated, and highly congested product 3d was obtained in 90% isolated yield and 89:11 er. Substitution of the internal positions was more detrimental to selectivity: N-benzylated product 3f was obtained in 86:14 er and propyl sulfonamide product 3g in 83:17 er. Product 3a demonstrated very high configurational stability, showing no sign of erosion in chiral purity after refluxing in toluene for ~15 hours (ΔG ‡ rac, 3a, 383 K > 36 kcal/mol, t1/2, 3a, 25 °C > 900,000 years). The presence and positioning of a blocking group on the nucleophile side (R 4 ≠ H, Figure ) proved essential for the success of the reaction. While its absence significatively hampered reaction rate (R 4 = H, 11% conv., ~90:10 er under scope conditions, see Figure ), moving the same blocking group on the opposite aryl ring, flanking the aryl fluoride, completely shut down reactivity (3h, Figure ). Interestingly, treating 2h under more forcing conditions (Cs2CO3, MeCN, rt, 15 h) only led to some intermolecular reactivity, and no trace of sevenmembered ring product was detected.