C4–H indole functionalisation: precedent and prospects

Abstract

This Perspective article traces the evolution of modern approaches to functionalise the indole C4–H bond.

PIDA‐Promoted Selective C5 C−H Selenylations of Indolines via Weak Interactions

“…[1] Thus, the modifications of indoles and indolines for the diversification of the scaffolds have received increasing attentions over the last few years. [3] Nevertheless, the derivation of indoles and indolines were generally limited to the C 1 -C 4 and C 7 positions governed by the effect of directing groups or the inherent nucleophilic reactivity, [4] while the site-selective CÀ H functionalization on the remote less activated C 5 position has remained a great challenge. [3] Nevertheless, the derivation of indoles and indolines were generally limited to the C 1 -C 4 and C 7 positions governed by the effect of directing groups or the inherent nucleophilic reactivity, [4] while the site-selective CÀ H functionalization on the remote less activated C 5 position has remained a great challenge.…”

“…[2] Recent advances in the transitionmetal catalysed direct CÀ H functionalization provided a powerful strategy for the modification of indole and indoline structures. [3] Nevertheless, the derivation of indoles and indolines were generally limited to the C 1 -C 4 and C 7 positions governed by the effect of directing groups or the inherent nucleophilic reactivity, [4] while the site-selective CÀ H functionalization on the remote less activated C 5 position has remained a great challenge.…”

An efficacious synthesis of N‐1–, C‐3–substituted indole derivatives and their antimicrobial studies

“…It is not surprising that a five‐membered nitrogen‐containing ring is an important structural motif in most pharmacores . Indole, a privileged scaffold, is widely known for its significance not only in the area of synthetic chemistry but also in biological, pharmaceutical, and material science . Indole derivatives have shown a wide range of biological activities such as plant growth regulation and antifungal, antibacterial, antitubercular, anticancer, antiulcer, antiviral, antioxidant, antidepressant, anti‐inflammatory, antidiabetic, antimalarial, anti‐HIV, insecticidal, and analgesic activities …”

Metal-supported and -assisted stereoselective cooperative photoredox catalysis

“…In particular, photoredox catalysis has emerged as a very powerful tool in organic synthesismore than 2000 publications witness its growing interest. The application ranges from natural product chemistry, [3][4][5][6][7] drug development and crop protection agents 8 to materials sciences (e.g., for polymers). [9][10][11][12][13] A particular feature of the last few years has been the development of visible light photoredox catalysis.…”