Breakthroughs in Indole and Indolizine Chemistry – New Synthetic Pathways, New Applications

Abstract

Indole and indolizines heterocyclic aromatic compounds structurally and chemically isomeric with indoles are an important class of N-fused heterocyclic compounds due to their interesting biological and optical properties. Different strategies for generating diverse collections of small molecules with indole and indolizine moieties have been developed. They can be synthesized by means of classical and nonclassical pathways. The present study discusses the versatile nature of indole/indolizine derivatives, new green methods for their synthesis, their possible mechanism of action and also provides information about current/future prospects of the topics and different indole/indolizine derivatives in pharmaceutical/clinical trials. With the remarkable number of approved indole-containing drugs as well as the importance of the indolizine moiety, it can be easily concluded that indole and indolizine derivatives offer perspectives on how pyrrole scaffolds might be exploited in the future as bioactive molecules against a broad range of diseases.

Cobalt-catalysed CH-alkylation of indoles with alcohols by borrowing hydrogen methodology

“…The resulting product constitutes an actual anti-cancer drug. 58 In general, aliphatic alcohols are less reactive compared to benzylic alcohols. Nevertheless, applying our catalyst, linear and cyclic aliphatic alcohols gave up to 69% of C3-alkylated indoles at slightly increased temperature and catalyst loading (Scheme 2; products 31–36 ).…”

Chiral Phosphoric Acid-Catalyzed Asymmetric Friedel–Crafts Addition of Indolizine to Cyclic N-Sulfonyl Imine

“…For example, homofascaplysin-C an alkaloid extracted from the marine sponge “Fascaplysinopsis reticulata” has been identified as a potent anticancer agent (Figure ). Moreover, structurally modified synthetic analogues of indolizine show impressive biological activities, such as anticancer, anti-inflammatory, antifungal and antiviral properties . In addition to their pharmaceutical relevance, indolizines exhibit strong fluorescence properties owing to their planar structure and aromatic electronic system, making them useful in the field of biomaterials …”

Continuous Flow Synthesis of Heterocycles: A Recent Update on the Flow Synthesis of Indoles

“…Arbidol is used for the treatment and prophylactic prevention of influenza A and B virus and SARS. Delavirdine is a first-generation non-nucleoside reverse transcriptase inhibitor that was approved by the FDA in 1997 for the treatment of human immunodeficiency virus type 1 (HIV-1) [ 4 , 5 ].…”