Current Green Chemistry - Volume 8, Issue 2, 2021

The starting of DDT production during World War II also signalized the beginning of a very rapid increase in pesticide use. Pesticides applied in the control of invertebrates are known as insecticides. On the other hand, vertebrates are controlled by rodenticides, which are used for killing rodents etc.; moreover, avicides are applied to repel birds, and piscicides are used in fish control. Herbicides are the most important in agriculture and are used for plant cultivation, moreover, fungicides are useful in killing fungi. Bactericides are used against bacteria, slimicides are used against slime-causing organisms in water, and algicides against algae. Many pesticides which were used in agriculture in the last 30-40 years are no longer authorised and have been replaced by pesticides on a non-chemical basis. Currently, the aim of the REACH Regulation in the European Union is to provide better protection for humans and the environment from possible chemical risks and to promote sustainable development. The European Chemicals Agency, established under this regulation and based in Helsinki, is responsible for managing the technical, scientific, and administrative aspects of REACH and for ensuring consistency in its application (www.europarl.europa.eu). In order to enhance the level of protection of human health and the environment, the same criteria for identifying labels for describing chemical hazards should be used throughout the EU and the world (www.europarl.europa.eu). This contribution briefly refers to the pesticides classification and their most commonly used detoxification.

Five- and six-membered N-heterocyclic compounds play an important role in medicinal chemistry and the development of new drugs. There is a constant demand for the development of novel biologically potent compounds, and there is also an increasing pressure to develop alternative and more sustainable synthetic methodologies following the Green Chemistry principles. Thus, the present review aims to compile the latest progress in the use of ultrasound irradiation in water conditions to mediate the synthesis of five- and six-membered N-heterocyclic compounds in an environmentally benign manner.

In this review, we focused on the six- and pseudo-six-component transformations in organic syntheses as a class of important and applicable MCRs. Although the MCRs usage in recent years is enhanced the reports for more than five-component MCRs are still rare. In some cases, these kinds of MCRs are the combination of some tandem named reactions that generated a union MCR. Preparation of multi-functionalized heterocycles, prevention of intermediate separation, reaction progressing in a one-pot continuous manner, elevated total yield, high atom economy, and preparation of potent bioactive multi-cycles hetero-organics via the construction of several new bonds are some highlighted features of MCRs. In this article, we classified the mentioned sixcomponent reactions based on reaction media. Another subdivision is applied based on thermal energy usage or ambient temperature. In fact, two aspects of the green chemistry rules have been discussed.

In recent times, Nickel has become a powerful alternative transition metal catalyst for performing cross-coupling reactions due to its low cost and better sustainability. Thus, a sustainable Nicatalyzed C-Se cross coupling has been developed in the presence of catalytic amount of copper iodide as co-catalyst. A wide range of substituted diaryl selenides has been synthesized by this Ni-Cu dual catalyzed C-Se cross coupling. The reaction is following an oxidative addition and reductive elimination pathway where Cu is playing an important role in transmetalation. The mechanism of the reaction was established by several experimental techniques.

Microwave irradiated facile and efficient process for one pot Ugi multicomponent reaction of a novel series of fluoroquinolone scaffolds is described here. On the basis of this approach, a new route to synthesize this privileged scaffolds was designed with higher yields, a clean procedure, time efficient and simple work-up. Our aim is to develop a biologically active fluoroquinolone scaffolds by microwave induced one pot Ugi multicomponent reaction. All the synthesized molecules were characterized by IR, ¹H NMR, ¹³C NMR, and Mass spectra. The antimicrobial activity of the synthesized compounds was screened against two Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), two Gram-positive bacteria (Staphylococcus aureus, Streptococcus pyogenes), and three fungi (Candida albicans, Aspergillus niger, Aspergillus clavatus) utilizing the MIC (Minimal Inhibitory Concentration) method and antitubercular activity H37Rv utilizing L. J. Slope method. Some of these novel derivatives demonstrate moderate to good in vitro antibacterial, antifungal and antitubercular activities.

Background: Iodination of the organic substrate is an important reaction for the synthesis of pharmacologically active molecules. Methods: In view of these concerns, we reported a convenient procedure for the synthesis of iodo compounds using iodine and iodic acid in PEG-400. We have reported an eco-friendly procedure for the preparation of aromatic iodo compounds using iodine and iodic acid in green reaction media as polyethylene glycol (PEG-400). Results: The iodination of some aromatic compounds such as benzaldehydes, acetophenones, phenols, amines, and heterocyclic compounds was carried out using iodine, iodic acid, and PEG-400. The synthesized substituted aromatic iodo compounds were confirmed based on the spectral characterization and mixed melting points. Conclusion: The method comprises several advantages such as simple reaction procedure, easy isolation, quantitative yields, and purity of iodo products.