Synthesis of 1-indolyl-3,5,8-substituted γ-carbolines: one-pot solvent-free protocol and biological evaluation

The anti-breast cancer potential of indole/isatin hybrids

Breast cancer (BC) is one of the most prevalent malignancies and the major contributor to cancer mortality in women globally, with a high degree of heterogeneity and a dismal prognosis. As drug resistance is responsible for most BC fatalities and advanced BC is currently considered incurable, finding innovative anti-BC chemotherapeutics is urgently required. Indole and its analog isatin (indole-1H-2,3-dione) are prominent pharmacophores in the development of novel medications, and their derivatives exhibit strong anticancer activities, also against BC. In particular, indole/isatin hybrids exhibit significant potency against BC including multidrug-resistant forms and excellent selectivity by influencing a variety of biological targets associated with the disease, supplying helpful building blocks for the identification of potential new BC treatment options. This review includes articles from 2020 to the present and provides insights into the in vitro and in vivo anti-BC potential, molecular mechanisms, and structure-activity relationships (SARs) of indole/isatin hybrids that may be helpful in the development of innovative anti-BC chemotherapeutics.

Synthesis of 5-aryl-3,3′-bis-indolyl and bis-7-aza-indolyl methanone derivatives from 5-bromo-7-azaindoles via sequential methylenation using microwave irradiation, CAN oxidation, and Suzuki coupling reactions

A catalyst-free and green chemical method has been developed for the methylenation of indole and N-methyl-7-aza indoles with aqueous formaldehyde afforded respective N,N′-dimethyl-3,3′-bis-7-azaindolylmethanes under microwave irradiation in excellent yield. Subsequent oxidation of the products thus obtained, using one electron chemical oxidant CAN afforded N,N′-dimethyl-3,3′-bis-7-azaindolylmethanone derivatives in excellent yield. This resulted in methanone derivatives with halogen substitution at the aryl ring which when subjected to Suzuki coupling with aryl boronic acids furnished highly functionalized fluorescent biaryl derivatives. Plausible mechanisms, characterization including XRD, and evaluation of photophysical properties of the Suzuki coupled products are described.

A catalyst-free methylenation of 7-aza indoles under MW irradiation and CAN oxidation of methylenated products to the respective ketones are achieved. Plausible mechanisms of the reactions and photophysical properties of the products are described.