A synthetic approach to carbazoles using electrochemically generated hypervalent iodine oxidant

Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance

“…98 The oxidation of iodobenzene in the presence of trifluoroethanol furnishes phenyliodine bis(trifluoroethoxide) (PIFE); Nishiyama and co-workers have extensively utilized this electrogenerated reagent to effect the oxidation of amides or hydroxamic acid derivatives into the corresponding nitreniums (Figure 6B). 99 The nitreniums thus generated can undergo cyclization with electron-rich arenes to afford quinoline scaffolds, 100 carbazoles, 101 or spirocycles 99 depending on the substitution patterns of the arene. This method has found applications in the synthesis of tetrahydropyrroloiminoquinone alkaloids (Figure 6C) as well as glycozoline (Figure 6D).…”

Elektrochemischer Durchlaufgenerator für hypervalente Iodreagenzien: Synthetische Anwendungen

“…Darüber hinaus wurde die a-Acetoxylierung [16] und die Tosylierung [14] von Acetophenon und Propiophenon mit dem gleichen Protokoll in hohen Ausbeuten erreicht, jedoch musste hier die Reaktionszeit auf bis zu 30 Minuten verlängert werden (Einträge 8-12). [17] Die Durchführung dieser Transformation unter Verwendung unseres Protokolls (10 min bei Zimmertemperatur) bildete das Carbazol nur in Spuren. [17] Die Durchführung dieser Transformation unter Verwendung unseres Protokolls (10 min bei Zimmertemperatur) bildete das Carbazol nur in Spuren.…”

Hypervalent Iodine Reagents by Anodic Oxidation: A Powerful Green Synthesis

“…In addition, the anodically generated iodine(III) reagent 30 is efficient for the oxidative cyclization of the phenyl acetanilide derivatives into the corresponding carbazoles. The reaction shows good functional group tolerance and the carbazole products were generally obtained in good yields . The feasibility of this carbazole synthesis was also confirmed by its application in the synthesis of the antibacterial and antifungal naturally occurring carbazole derivative glycozoline 58 (Scheme ).…”