Date of Graduation
Eberly College of Arts and Sciences
Several new methodologies for synthesizing functional 1,2,3-triazoles which include arylation, vinylation, propargylation and allenation, have been successfully developed. These resulting new methods are of great benefit to the organic chemists who are working on the research fields related to 1,2,3-triazoles. Particularly, the iron catalyzed propargylation and allenation have initiated the iron chemistry with 1,2,3-triazoles as the ligand. For example, our efforts led to the discovery of a practical approach for the synthesis of conjugated enynes that is challenging through conventional methods. In the synthesis of conjugated enyne, 1,2,3-triazoles were revealed as the only ligand effectively promoting this important and challenging transformation (gave up to 95% yields). Other tested N-heterocycles, including the 1,2,4-triazole, tetrazole, and pyridine, all gave poor results (< 10%) even with similar binding pattern, which demonstrating the unique role of 1,2,3-triazole in iron catalysis.;In addition, the complexes [Ir(L.;X)(ArTriaz)2] and [Ir(bbpy)(ArTriaz)2]Cl have been successfully prepared through N-2-aryl-1,2,3-triazoles as the efficient binding ligands in coordination with iridium salt in excellent yields. These air and moisture stable Ir(III) complexes showed effective catalytic reactivity in photoredox catalysis.;The N-2-aryl-1,2,3-triazole derivatives (NATs) were developed as a new class of UV/blue-light-emitting fluorophores. Though both N-1-aryl-1,2,3-triazoles and N-2-aryl-1,2,3-triazoles gave strong photo absorption under excitation at 330 nm, only the N-2-analogous showed strong fluorescence emission in the UV/blue range with high efficiency in various solvents. The computational studies along with X-ray crystal structures indicated the significance of the effective conjugation between triazole ring and aryl groups on the N-2 position. The planar intramolecular charge transfer (PICT) mechanism was proposed, which was supported by solvent effect studies.
Yan, Wuming, "Synthesis of Functional 1,2,3-Triazoles and Its Applications in Transition Metal Catalysis" (2012). Graduate Theses, Dissertations, and Problem Reports. 4941.