Pentafluorophenol-Catalyzed Metal-Free Fischer Indole Synthesis: A Novel Approach to Carbazole Derivatives and Desbromoarborescidine A.

Carbazoles represent significant heterocyclic compounds with a wide range of applications in organic synthesis. Conventional techniques, such as the Fischer indole synthesis, have been extensively utilized for the construction of these structures. In this study, we report the first use of pentafluorophenol (PFP) as a catalyst in a metal-free approach for the synthesis of carbazoles.

A Practical and Metal-Free Approach Towards Synthesis of Spiro-Benzazepinoindole Derivatives via Pentafluorophenol Catalyzed Pictet-Spengler Reaction.

The efficient pentaflurophenol-catalyzed Pictet-Spengler cyclization was carried out which led to the formation of spirobenzazepinoindole. This article examines the methods and modifications of Pictet-Spengler cyclization in the synthesis of intricate organic compounds, emphasizing its significance in drug discovery and development. This reaction generally entails the condensation of an amine with an aldehyde or ketone, succeeded by an intramolecular cyclization step catalyzed by pentafluorophenol, an alternate for metal-mediated catalysts due to its facile characteristics which render it an invaluable asset in organic synthesis and catalysis.