Mini-Reviews in Organic Chemistry - Volume 15, Issue 1, 2018

Background: The Diels-Alder reaction is one of the most important reactions in organic synthesis. Objective: Recently there has been considerable interest in conducting this important reaction in aqueous or semi-aqueous media using organocatalysts due to the green nature of the water solvent and organocatalysts as well as the special solvent effects of water on organic reactions. Conclusion: This review attempts to summarize the most recent developments in organocatalytic asymmetric Diels-Alder reactions using water as a solvent or a co-solvent.

Background: Microalgae cultures are an interesting option for industrial effluent treatment due to their capacity to use these wastes as a nutritional source in the culture medium, producing a biomass that is rich in high-value biocompounds. Objective: This review aims to explore the industrial effluents that are mostly used as a nutritional source in microalgal cultivation, as well as the concepts of white biotechnology, cyclical processes in microalgal cultures and the bioproducts obtained through these systems. Conclusion: The implementation of wastewater-based microalgae cultivation for this purpose makes industrial processes more sustainable and less expensive by replacing the technologies that are usually applied to remove the contaminants. Through these cultivation systems, substantial amount of water and nutrients such as carbon, nitrogen and phosphorus can be recovered.

Background: Thioureas are widely used as intermediates in organic synthesis, and they are commonly used in several classes of heterocycles. Objective: There has been an escalating interest in the development of heterocycles employing thioureas as building blocks. Furthermore, thioureas can be utilized as a reagent in a synthesis of a large number of therapeutic agents. In addition, substituted thioureas have recently gained much interest in the preparation of a wide variety of biologically active compounds. Conclusion: This review highlights the status of thiourea scaffolds in the drug development and heterocyclic synthesis described in the literature mainly since 2010.

Background: Aquilaria, a genus belonging to the Thymelaeaceae, produces fragrant resinous agarwood, also known as eaglewood, which has been used as incense since old times. The intense fragrance is the result of the presence of a wide variety of secondary metabolites. Objective: This genus was reported contained sesquiterpenes, chromones, flavonoids, benzophenones, diterpenoids, triterpenoids, and lignans. Conclusion: Here, we review the different secondary metabolites that have been identified in Aquilaria to show their diversity and to allow comparison with other Thymelaeaceae genera.

Background: Acquired immunodeficiency syndrome or (AIDS) is a malady which is caused by HIV (human immunodeficiency) virus and affects individuals on all continents. In the year 1987, the antiretroviral therapy began improving the eminence of life for AIDS patients and increased the survival rates. Abacavir is an antiretroviral drug approved by FDA in 1998, and is widely employed in the treatment of AIDS. Objective: This review aims to examine gravely the various synthetic methodologies used for the synthesis of abacavir. Carbocyclic nucleosides synthesis remains a dynamic field of research in medicinal area. Various consistent and effective synthetic protocols for abacavir are accessible to researchers which affords the drug in high yields as well as high regio- and stereoselectivity. Conclusion: An effort has been carried out to provide an overview of the selected methods, main focus will be on palladium catalyzed coupling and ring-closing metathesis. Resolution of intermediates involved in the synthesis has also been tinted briefly.

Background: The species of genus Streptocaulon are well known for their traditional uses in the treatment of various diseases like dysentery, influenza, stomachache, chronic nephritis and traumatic injury. Objective: In recent years, the genus Streptocaulon has been studied for its chemical constituents and biological activities. The cardiac glycosides and triterpenoids are the major constituents of this genus and most of cardiac glycosides exhibit anti-proliferative effects. Conclusion: The aim of the present paper is to review the comprehensive knowledge of the compounds isolated from this genus including the chemical structures and biological activities.

Background: Polycyclic aromatic hydrocarbons (PAHs) are a major class of organic pollutants that are widely distributed in the environment and cause human disease and harm the ecological environment. Objective: The principle processes for their successful removal from the environment (such as soil, sediment, or water) are currently believed to be microbial transformation and degradation. Results: Studying the metabolic pathways involving PAHs and identifying the functional regulation of proteins involved in biodegradation will lead to their more effective and controllable bioremediation with the application of degrading bacteria.