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Since December 2019, humanity has faced an important global threat. Many studies have been published on the origin, structure, and mechanism of action of the SARS-CoV-2 virus and the treatment of its disease. The priority of scientists all over the world has been to direct their time to research this subject. In this review, we highlight chemical studies and therapeutic approaches to overcome COVID-19 with seven different sections. These sections are the structure and mechanism of action of SARS-CoV-2, immunotherapy and vaccine, computer-aided drug design, repurposing therapeutics for COVID-19, synthesis of new molecular structures against COVID-19, food safety/security and functional food components, and potential natural products against COVID-19. In this work, we aimed to screen all the newly synthesized compounds, repurposing chemicals covering antiviral, anti-inflammatory, antibacterial, antiparasitic, anticancer, antipsychotic, and antihistamine compounds against COVID-19. We also highlight computer-aided approaches to develop an anti-COVID-19 molecule. We explain that some phytochemicals and dietary supplements have been identified as antiviral bioproducts, which have almost been successfully tested against COVID-19. In addition, we present immunotherapy types, targets, immunotherapy and inflammation/mutations of the virus, immune response, and vaccine issues.

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NewN-acylamino-substituted tricyclic imides have been screened for scavenging ability against the free radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), chelating activity on ferrous ions, and reductive potential. The results were compared with synthetic antioxidants BHT, BHA, and Trolox. The compounds exhibited different levels of antioxidant activity in all tests.

The CÀC coupling of the two bicyclic, unsaturated dicarboximides 5 and 6 with aryl and heteroaryl halides gave, under reductive Heck conditions, the C-aryl-N-phenyl-substituted oxabicyclic imides 7a -c and 8a -c (Scheme 3). Domino-Heck CÀC coupling reactions of 5, 6, and 1b with aryl or heteroaryl iodides and phenyl-or (trimethylsilyl)acetylene also proved feasible giving 8, 9, and 10a -c, respectively (Scheme 4). Reduction of 1b with LiAlH 4 (! 11) followed by Heck arylation and reduction of 5 with NaBH 4 (! 13) followed by Heck arylation open a new access to the bridged perhydroisoindole derivatives 12a,b and 14a,b with prospective pharmaceutical activity (Schemes 5 and 6).Introduction. -Due to its broad synthetic potential as a stereoselective CÀC coupling method, the Heck reaction has been the subject of several synthetic and mechanistic studies over the last 30 years [1 -5]. Originally developed to arylate acyclic alkenes, the reaction scope has been extended to cyclic compounds later, too. Rigid biand multicyclic systems make the catalytic oxidative Heck-coupling reaction impossible. To circumvent this problem, domino-Heck reactions were introduced with a hydroarylation reaction as its simplest variant [6 -8], leading to a reductive CÀC coupling reaction. Kaufmann and co-workers have been carrying out new examples of reductive Heck reactions using bicyclic systems aiming at the synthesis of new biologically active compounds [9 -15].In our previous works, we have accomplished Pd-catalyzed domino-Heck applications of bi-and tricyclic precursors of epibatidine analogs [16]. We then focused on reductive Heck reactions of polyfunctional tricyclic molecules with a strained C¼C bond and an N-(acylamino)imide group [17].Later, we became interested in the synthesis of bioactive norcantharidin analogues 3 and 4b that represent aryl-modified bicyclic imide systems, too. We had first synthesized N-phenylbicyclo[2.2.1]hept-5-ene-2-endo,3-endo-dicarboximide (1a) and N-phenyl-7-oxabicyclo[2.2.1]hept-5-ene-2-exo,3-exo-dicarboximide (1b) as starting compounds according to [18] [19]. We then investigated their hydroarylation reactions with aryl-and heteroaryl iodides (ArI) in the presence of Ph 3 As giving 2a,b and subsequent reduction reactions by LiAlH 4 to open a new access to perhydroisoindole derivatives 4a,b [20] (Scheme 1). In reductive arylation reactions, Ph 3 As has proved to be superior to Ph 3 P and carbenes as ligands in both selectivity and yield [21].