Graphical abstract

Oxygen-containing heterocycles are largely distributed in natural and synthetic compounds. Coumarins are among the most famous heterocycles which possess one oxygen atom in their rings. Coumarins are classified as multifunctional scaffold and are used as anti-oxidant reagents, anti-inflammatory, anti-microbial, anti-fungal, anti-HIV active, analgesic, anti-histaminic, insecticides, dyes, herbicides, sensitizers, perfumes, cosmetics and food additives. Due to their diverse applications in industrial and pharmaceutical fields, many chemists have given significant interest to these compounds. Herein, the review highlights various methods for the synthesis and interactions of coumarin moiety as one of the most efficient categories of heterocycles.

No abstract

The pyrazolopyrazine ring system is a very interesting class of heterocyclic compounds that were considered as important scaffolds of many efficacious biologically active agents that show anticancer with low toxicity, antioxidant, anticonvulsant, antiparasitic, anti‐inflammatory, antiviral, antibacterial, antifungal, and analgesic activities. This review throws light on the detailed synthetic approaches for the synthesis and reactions of pyrazolopyrazine moiety. This follow up may encourage the chemists to generate new routes possessing pyrazolopyrazine nucleus with high efficacy.

Graphical abstract