Design and synthesis of some novel 7-substituted thiosemicarbazinyl-quinolines via Ullmann coupling reaction and examination of their antimicrobial activities

Recent update on antibacterial and antifungal activity of quinoline scaffolds

Although most of the heterocycles have been reported to possess a significant pharmacological activity, only a few of them, namely quinoline derivatives, have exhibited the finest biological activities. Despite the few medicinal properties of the plain quinoline molecule, its derivatives exhibit diverse pharmacological properties such as anticancer, anti-inflammatory, antibacterial, antiviral, antifungal, antiprotozoal activities, and so on. The potential antimicrobial properties of the quinoline derivatives are evident from the decades of research on these derivatives. Owing to limitations like drug resistance, high cost, severe side effects, and less bioavailability of previously synthesized antimicrobial agents, these drugs have become obsolete in recent years. Hence, the design of more efficient antimicrobial drugs must be given topmost priority. A breakthrough in drug discovery is a must to prevent malevolent microbial diseases. Addressing all these issues, researchers have been continuously contributing to antimicrobial drug discovery. Herein, a short description of the pharmacology of antimicrobial agents such as antibacterials and antifungals synthesized recently is provided. The versatile derivatization of the quinoline moiety leading to significant antimicrobial potencies is discussed, considering the structure-activity relationship.

Synthetic and computational studies on CuI/ligand pair promoted activation of C(Aryl)-Cl bond in C-N coupling reactions

Cu/ligand-mediated coupling reactions have been widely investigated in the recent past. However, activation of cheaper aryl chlorides is still a great limitation of these reactions. During the course of present investigations efforts have been made to develop a normal and facile CuI/ligand pair protocol for arylation of phthalimide using aryl chlorides. The protocol has also been extended for arylation of amines. On the basis of experimental and theoretical results, a catalytic cycle has also been proposed and it has been established that these reactions follow oxidative addition-reductive elimination (OA-RE) pathway. These studies have indicated that tetracoordinated [Cu(L1)(L2)]⁺ complex is active catalytic species in these reactions.