A variety of functionalized N-alkylated carbazolones were prepared via N-alkylation of 3-(arylamino)cyclohex-2-enones followed by an intramolecular oxidative coupling mediated by Pd(OAc)2 under an oxygen atmosphere. This approach adopts an inverted sequence, consisting of the conventional annulation and subsequent N-alkylation.
A variety of N-substituted 3-aminocyclohex-2-enones were converted into the corresponding N-arylated α-iodo enaminones in high yields via concurrent α-iodination and N-arylation mediated by ArI(OAc)2. A mechanism is postulated to account for the reaction differences between the cyclic and the acyclic β-enaminones, which undergo predominant α-acetoxylation under the same reaction conditions.