Abstract
The indole ring is one of the most abundant heterocyclic scaffolds found in nature. It is built into the essential amino acid tryptophan in which the arene component of the indole facilitates π-π interactions, and the N-H group serving as a hydrogen bond donor to proximal proteinogenic species. Accordingly, the indole sub-structure forms an essential component of the framework of higher order protein structures. Although myriad synthetic routes exist to access the indole nucleus including the venerable Fisher indole synthesis and other named reactions, new methods and modifications to the existing methods remain a key area of research. Drivers include improving regioselectivity for functionalizing the core, and the need for greener approaches. Microwave and flow mediated methods have been an area of significant interest to address these issues, and this mini review will survey recent advances in the field.
Keywords: Flow, indoles, medicinal, microwave, tryptophans.
Graphical Abstract
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