Pentafluorophenol (C<sub>6</sub>F<sub>5</sub>OH) Catalyzed Pictet‐Spengler Reaction: A Facile and Metal‐Free Approach Towards Tetrahydro‐<i>β</i>‐Carbolines
Rina Mahato, Chinmoy Kumar Hazra
Abstract
Herein, we have disclosed pentafluorophenol as an operative catalyst for synthesizing (spirocyclic) tetrahydro-β-carbolines via the Pictet-Spengler reaction. This straightforward catalytic protocol works under mild conditions resulting indole alkaloids in excellent yield with remarkable functional group tolerance, including late-stage modifications. This transformation demonstrates a practical and adaptable approach to produce a highly effective gram-scale synthesis of the natural alkaloid Komavine and enables the synthesis of the commercial drug Tadalafil.
Topics & Concepts
Pictet–Spengler reactionCatalysisIndole testYield (engineering)Combinatorial chemistryChemistryFunctional groupOrganic chemistryMaterials sciencePolymerMetallurgySynthesis and bioactivity of alkaloidsSynthesis of Indole DerivativesChemical synthesis and alkaloids