Synthesis, reactivity and biological properties of methoxy-activated indoles

Abstract

Indoles continue to play a central role in the development of new structures of chemical and biological interest. They are the source of numerous biologically active natural products by virtue of their derivation from tryptophan units which are essential to peptide, protein and enzyme structures. Although the indole unit is electron rich and displays a wide range of reactivity, many naturally-occurring indoles contain methoxy substituents, which enhance their reactivity. The synthesis of methoxyindoles has also become a strategy for diversifying the regiochemical behaviour of indoles. This review brings together a wide range of information relating to indoles incorporating one, two, or three methoxy groups. It deals with aspects of synthesis, reactivity, and biological activity as well as summarizing the scope of important natural products.