Facile access to 3-cyano-4-azaindoles via a modified Madelung indole synthesis

A Tandem Madelung Indole Synthesis Mediated by a LiN(SiMe3)2/CsF System

A tandem Madelung indole synthesis by the reaction of methyl benzoate and N-methyl-o-toluidine has been discovered. The combination of LiN(SiMe3)2 with CsF is the key factor, which secures the high efficiency of such tandem transformations. Simply combining methyl benzoate, N-methyl-o-toluidine LiN(SiMe3)2, and CsF generated a diverse array of N-methyl-2-phenylindoles (31 examples, 50-90% yields). Furthermore, the scalability and the poststructural modifications of this indole synthesis were demonstrated.

Research progress on the structure and biological diversities of 2-phenylindole derivatives in recent 20 years

The privileged structure binds to multiple receptors with high affinity, which is helpful to the development of new bioactive compounds. Indole is classified as a privileged structure, which may be one of the most important structural categories in drug discovery. As a special subset of indole compounds, 2-phenylindole seems to be one of most promising forerunners of drug development. In this paper, 106 articles were referenced to review the structural changes, biological activities and structure-activity relationship of compounds in recent 20 years, and classified them according to their pharmacological activities, from several aspects, including anticancer, antibacterial, anti-inflammatory, analgesic, antiviral, anti-parasite, the biological activities target to central nervous system, et al. It also points out the importance of artificial intelligence (AI) technology in discovery of new 2-phenylindole compounds in a broader prospect. This review will provide some ideas for researchers to develop new indole drugs.

Recent developments in the synthesis of azaindoles from pyridine and pyrrole building blocks

The azaindole framework is ubiquitous in bioactive natural products and pharmaceuticals. This review highlights the synthetic approaches to azaindoles with advantages and limitations, mechanistic pathways and biological importance.

Mg3N2-assisted one-pot synthesis of 1,3-disubstituted imidazo[1,5-a]pyridine

A novel Mg₃N₂-assisted one-pot annulation strategy has been developed via cyclo-condensation reaction of 2-pyridyl ketones with alkyl glyoxylates or aldehydes, allowing the formation of imidazo[1,5-a]pyridines exclusively with an exellent yield.

Facile synthesis of 4- and 7-azaindoles from the corresponding imines by palladium-catalyzed cascade C-C and C-N coupling

The cyclization of 2,3-dihalopyridines with readily available imines provides a convenient and regioselective approach to 4- and 7-azaindoles. The regioselectivity can be controlled by the choice of the halogen atoms at the pyridine ring (chlorine versus bromine).