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

Abstract

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. Spectroscopic methods like NMR (1H & 13C), IR, and mass spectrometry were used to comprehensively analyze the produced spirobenzazepinoindoles. This method signifies the synthesizing spirobenzazepinoindole enhances efficiency, selectivity, and cost-effectiveness while enabling access to novel compounds with potential pharmacological applications.

Keywords: Pictet-Spengler Cyclization, pentafluorophenol, indole, isatin, ninhydrin, spirobenzazepinoindole.