Novel chemistry of indole in the synthesis of heterocycles

Abstract

Indoles that are substituted at the 2-or 3-position with electron-withdrawing groups (nitro, phenylsulfonyl) undergo nucleophilic addition, 1,3-dipolar cycloaddition, and Diels-Alder reactions to give a variety of indoles, pyrroloindoles, and carbazoles. New methods for the synthesis of furo [3,4-b]indoles and the novel ring system furo[3,4-b]pyrrole are described for the first time. Diels-Alder reactions of furo [3,4-b]pyrroles afford indoles after dehydration of the primary cycloadducts. Efficient syntheses of both 2-and 3-nitroindoles from indole are reported, and the first generation and successful electrophilic trapping of a 2,3-dilithioindole has been achieved.

Simple Preparation of New Potential Bioactive Nitrogen-Containing Molecules and Their Spectroscopy Analysis

“…In the past decades, a lot of interest has been shown in the preparation of substituted indoles due to their numerous biologically significant activities (Gribble, 2003). The derivatives of 3-indolylmethanamine 1 are the important intermediates of natural and natural-like products, such as hydro--carboline and pyrido [4,3-b]indole derivatives (Wynne & Stalick, 2002;Molina et al, 1996).…”

Transition Metal‐Catalyzed Synthesis of Fused Five‐Membered Aromatic Heterocycles

“…Consequently, the indole ring system has become an essential, or so called privileged, structural motif in many pharmaceutical agents [156,158]. Furthermore, indole-containing structures have found widespread application as materials with an array of valuable properties [5,156,158,159], as well as reactive intermediates in the synthesis of fine chemicals [6,9,64,[160][161][162][163][164]. Not surprisingly, investigation of the chemistry of this fascinating heterocycle has been sustained to be one of the most important objectives of heterocyclic chemistry for over 100 years.…”

Harnessing the Chemistry of the Indole Heterocycle to Drive Discoveries in Biology and Medicine

“…The chemistry of indole ( 1 ) is both basic and unique; however, we are still learning to harness this heterocycle for innovations in synthetic methodology, natural product synthesis and chemical biology. This provides rich opportunities for extensive synthetic exploration to enable the construction and development of indole compounds to explore for drug discovery.…”

“…The chemistry of indole (1)i sb oth basic and unique; [19][20][21][22] however, we are still learning to harness this heterocycle for innovations in synthetic methodology,n atural product synthesis and chemical biology.T his provides rich opportunities for extensives ynthetic exploration to enablet he construction and development of indole compounds to explore for drug discovery.T his review presents some basic indole chemistry (with reactions and mechanisms providedt hroughout), clinically used indole-based compounds, complex indole alkaloids along with biosynthetic knowledge and indole-inspired discovery efforts by several research groups interested in utilizing novel indolebased small molecules to drive discoveries important to human health and medicine (Scheme 1).…”