Current Organic Chemistry - Volume 24, Issue 15, 2020

We have explored the reactions of tetrahydro-4H-selenochromenes in the presence of phosphoric pentachloride, and synthesized new condensate aroylbenzoselenophenes. During the reactions, tetrahydro-4H-selenochromenes with phosphoric pentachloride underwent oxidative aromatization and nucleophilic substitution for a chlorine atom of one of the protons in the alicyclic fragment. Also, the narrowing of the heterocyclic fragment occurred as in synthesized selenium-containing compounds earlier transformed into the corresponding condensate aroylbenzoselenophenes.

Perimidines are peri-naphtho-fused derivatives of pyrimidine. They are of particular interest as they are a rare example of an azine in which the lone pair of electrons of pyrrole-like nitrogen participates in the π-system of the molecule. Perimidine is an interesting class of heterocyclic compounds. Various synthetic analogs of perimidines have been prepared and evaluated for many pharmacological activities in different models with desired findings. They exhibit biological activities as antitumor, antiulcer, antimicrobial, and antifungal agents. This review is an attempt to organize the synthesis and chemical reactions of perimidine analogs reported to date systematically since 1955. It should be noted that this review is the first one that includes the preparation and reactions of the perimidine ring.

The search for novel nucleosides has been a major research focus in medicinal chemistry for several decades, particularly given their proven track record in the treatment of viral infections and cancer. As bioisosteres of natural nucleosides, thionucleosides are especially attractive targets as they often display improved biological activity. Furthermore, the replacement of oxygen with sulfur may sometimes be accompanied by interesting changes in pharmacological effect. This update covers recent advances in the preparation of novel thionucleosides, grouped by synthetic strategy. The biological properties of the target thionucleosides are also summarised, in addition to any reported structure activity relationships.

Ionic liquids can be utilized in petroleum science. However, significant attention has been paid to the utilization of ionic liquids in petroleum science by researchers. In this work, the recent development of the utilization of ionic liquids in petroleum science is introduced. First of all, ionic liquids can be utilized as an additive in the oil & gas industry, such as a surfactant, corrosion inhibitor, demulsifier, and dispersant. In addition, ionic liquids can be utilized in the separation process of oil & gas processing. For example, ionic liquids can be utilized to remove naphthenic acids from oils, extract toluene from alkanes, dissolution of asphaltene in oils, extract phenol from model oil, and separate oil mixtures in a combination of membranes. Ionic liquids can also be utilized in novel technology development for enhanced oil recovery, and oil field scale control process. Moreover, utilization of ionic liquids in gasoline desulfurization process is important and crucial, which is greener, lower cost, and safer compared with the traditional processing technology. Furthermore, ionic liquids can be utilized as novel solvents to form micro-emulsion. Some ionic liquids have task-specific functional groups, which can reduce the cost and improve the separation efficiency. The utilization of ionic liquids in the catalysis process of the oil & gas industry is also introduced in this work. In the end, the utilization of ionic liquids in the oil sand treatment process and asphaltene precipitation inhibition process is discussed. This work will benefit the novel environmentally friendly technology development using ionic liquids for oil & gas production and processing.

Achieving challenging molecular diversity in contemporary chemical synthesis remains a formidable hurdle, particularly in the delivery of diversified bioactive heterocyclic pharmacophores for drug design and pharmaceutical applications. The coupling methods that combine a diverse range of readily accessible and commercially available pools of substrates under the action of earth-abundant first row transition metal catalysts have certainly matured into powerful tools, thus offering sustainable alternatives to revolutionize the organic synthesis. This minireview highlights the successful utilization of the catalytic ability of the first row transition metals (Mn, Fe, Ni, Cu) in the modular assembly of quinazoline heterocycle, ubiquitously present in numerous alkaloids, commercial medicines and is associated with a diverse range of pharmacological activities. The broad substrate scope and high functional group tolerance of the targeted methods were extensively explored, identifying the future strategic advances in the field. The investigation will also be exemplified with mechanistic studies as long as they are deemed necessary.