Seven membered heterocyclic Azepine and its derivatives have great pharmacological and therapeutic implications. In this review, the literature of the last fifty years has been exploited for the synthesis, reaction, and biological properties of these seven-member heterocyclic compounds. Most of the mechanisms involved the ring expansion of either five or six-membered compounds using various methods such as thermally, photo-chemically, and microwave irradiation. The systematically designed schemes involve the synthesis of different derivatives of azepine, azepinone, azepane, etc., using similar moieties by various researchers. However, there is much work yet to be done in the biological section, as it is not explored and reported in the literature; therefore, N-containing seven-membered heterocycles still have much scope for the researchers.

Heterocycles are significant class of compound in organic chemistry, due to their substantial pharmacological application and development of new materials, as well as their prevalence in natural products. Pyrazine is one of the most essential types of N-heterocycles, which is a useful compound in organic chemistry and has a wide range of commercial applications. It has recently been the focus of a number of techniques, owing to its widespread use as a framework in the synthesis of bioactive components, catalysts, and reactions in various media. Pyrazine compounds comprise a variety of pharmacological action, including antipyretic, anti-inflammatory, analgesic, anticancer, antibacterial, and antioxidant activity. It can be used to carry out different types of coupling reaction i.e., Suzuki, Buchwald Hartwig, oxidative coupling reactions. This review aims to summarize the recent work done pyrazine synthesis and the latest report of the last six years going in the field of pyrazine synthesis.

Background: Recently, the application of cancer nanotechnology-based drug delivery to cancer cells has arisen as an important method to resolve multiple molecular, biophysical, and biochemical obstacles, which the body is preparing to resist against the productive implementation of chemotherapeutic medications. Drug delivery technologies focused on nanoparticles, which have resolved some of the drawbacks of conventional chemotherapy as, decreased drug viscosity, chemo-resistance, precise malignity, limited medicative measures with low oral bioactivity. Due to their adjustable size and surface properties, the half-life period of a drug can be increased in the bloodstream. Objective: The aim of the current study is to collect and document the data available on the drug delivery system for anticancer drugs. The present study includes some of the drug carriers like liposomes, carbon dots, micelles, carbon nanotubes, magnetic nanoparticles, etc. Methods: To write this review, an exhaustive literature survey was carried out using relevant work published in various SCI, Scopus, and non-SCI indexed journals. The different search engines used to download the research/ review papers are Google search, PubMed, Science Direct, Google Scholar, Scientific Information Database and Research Gate, etc. Results: Nanotechnology offers better pharmacokinetics, reduces the systematic toxicities related to the chemotherapies and a better route of drug administration. In the analysis, we critically highlight recent studies on carcinoma-fighting nanotechnology. Conclusion: In the present study, different kinds of nano-based drug delivery systems have been discussed along with their characteristic features, the encapsulation of anticancer agents into different types of nanometresized vehicles and their general mechanism.

Trimetallic nanoparticles are a versatile class of nanoparticles that deliver enhanced stability and multifunctionality. Their structural and electronic properties makes them significant for energy conversion and biomedical applications.

Most of the heterocyclic compounds are pharmaceutically active and have numerous applications in various industries. Rigorous effects have been done and still going on in the search for more dynamic and advantageous compounds. Many researchers have focused their work on the synthesis of lower member heterocyclic compounds. However, not many efforts have been made for the higher membered compounds, though having equipotency. The aim of the current study is to collect and document the data available in the seven-membered heterocyclic compounds i.e. oxepin and thiepine compounds. The present study includes natural sources, drugs, synthetic methods, reactions, and biological activities of these compounds and their derivatives. Various seven-membered heterocyclic compounds have been synthesized via Friedel-craft Cyclization, Ullmann cross-coupling, Sonogashira coupling, and etc. However, biological potencies have still not been explored much by the researchers. This encouraged us to write this book chapter, as it has too much scope for future research.