Novel Synthesis Of1,2,3-Triazole Compounds And Their Bioactivities

1,2,3-triazole compounds and their derivatives have found widespread applications in various different areas including bioconjugations, polymer, surface science, pesticides and pharmaceuticals. In recent years, the introduction of trifluoromethyl and difluoromethyl group (-CF3and-CF2H) into biologically active compounds has attracted much interest due to their special physical and chemical properties, such as high electronegativity. increased lipophilicity and improved bioavailability. Multicomponent one-pot reactions have proven to be a practical and efficient method to access complex structures and compounds library from simple building blocks. Compared to the classical step-by-step formation of individual bonds for the target compounds, multicomponent reactions (MCRs) take advantage of the simultaneous formation of several bonds in a single step. In this dissertation, we developed two novel methods for the contruction of CF2H or CF3-containing1,2,3-triazole through three-component one-pot reaction without the isolation of the organic azides. We also synthesized a series of5-trifluoromethyl-1,4,5-trisubstituted1,2,3-triazole via a copper-catalyzed direct trifluoromethylation of5-iodo-1,2,3-triazole with Ruppert’s reagent. Carboxylicacid-containing1,2,3-triazoles were prepared and used to construct a series of1,2,3-triazole-containing the analogs of Chlorantraniliprole. In the last chapter of this dissertation, we described a novel and efficient method for the synthesis of polyfluoro-substituted unsymmetrical biaryl ethers via oxygen-promoted Ni-catalyzed coupling of arylboronic acids with polyfluoroarenes.1. In this chapter, we firstly designed and synthesized a novel difluoro-containing building block,2,2-difluoro-2-phenylsulfanyl-ethanol. Then fourteen difluoromethyl-containing1,4-disubstituted1,2,3-triazoles were synthesized via a novel copper-catalyzed click-multicomponent reaction of2,2-difluoro-2-phenylsulfanyl-ethanol, sodium azide and terminal alkynes in the presence of N-(p-toluenesulfonyl)imidazole, tetrabutylammonium iodide and triethylamine, followed by reductive cleavage of the phenylsulfanyl group using tributyltin hydride and azobisisobutyronitrile. Insecticidal activities of some title compounds and intermediate were tested.2. We reported a novel approach for the synthesis of CF2H or CF3containing1-aryl-1,4,5-trisubstituted1,2,3-triazoles by a one-pot three-component reaction of arylboronic acids, sodium azide and active methylene ketones in the presence of Cu(OAc)2and piperidine using a DMSO/H2O (10/1) mixture as solvent. The outstanding advantage of this method is that it avoids the isolation of the unstable and hazardous arylazides. It provides a new and practical one-step route to synthesize the structural diversity of1-aryl-1,4,5-trisubstituted1,2,3-triazoles from easily commercially available boronic acids. Insecticidal activities of some title compounds and intermediate were tested. Insecticidal activities of some target compounds were tested.3. A series of5-iodo-1,4,5-trisubsitituted-1,2,3-triazole were firstly prepared from1-iodoalkynes and organic azides. Furthermore5-trifluoromethyl-1,2,3-treiazole were synthesized via a metal-catalyzed direct trifluoromethylation of5-iodo-1,2,3-triazole in the presence of trifluoromethyltrimethylsilane、copper iodide、potassium fluoride、 phenanthroline and silver carbonate. Insecticidal activities of some title compounds and intermediate were tested.4.4-Carboxylic acid1,2,3-triazoles were prepared and used as building blocks to construct ten1,2,3-triazole-containing the analogs of Chlorantraniliprole. Insecticidal activities of the all title compounds were tested.5. Polyfluoro-substituted unsymmetrical biaryl ethers were synthesized via a novel Ni-catalyzed cross-coupling reaction of polyfluoroarenes with arylboronic acids and oxygen. The polyfluorinated arenes presumably capture the phenoxide intermediate efficiently, which made the oxygen-insertion proceed smoothly via the SNAr protocol. The18O labeling experiment demonstrated that the oxygen introduced into unsymmetrical diaryl ether originated from very trace amounts of oxygen in the reaction system. A plausible mechanism was also suggested.