magistrsko delo
Mateja Žnidarič (Author), Martin Gazvoda (Mentor), Jurij Lah (Thesis defence commission member), Janez Košmrlj (Thesis defence commission member)

Abstract

Cilj magistrskega dela je bila sinteza izbranih triazolijevih soli, funkcionaliziranih z dvema piridinskima substituentoma, kot potencialnih ligandov za organokovinske komplekse s paladijem in ostalimi kovinami prehoda. Uspešno smo sintetizirali dve takšni triazolijevi soli. Ogrodje obeh predstavlja 1,4-di(piridin-2-il)-1H-1,2,3-triazolijeva sol, ki je v enem primeru na mestu 3 metilirana, v drugem pa arilirana. Literaturna sinteza pot do metilirane spojine poteka preko 1,4-di(piridin-2-il)-1H-1,2,3-triazola, ki ga metiliramo, pri tem v večinskem deležu nastane stranski produkt, kjer metiliranje v večji meri (75%) poteče na piridinskem dušiku, pri tem nastane 25% želene triazolijeve soli. Izhodni 1,4-di(piridin-2-il)-1H-1,2,3-triazol smo pripravili s ''klik'' reakcijo med 2-azidopiridinom in 2-etinilpiridinom, kjer smo preizkusili tri različne bakrove katalizatorje in optimizirali reakcijske pogoje. Iz 1,4-di(piridin-2-il)-1H-1,2,3-triazola smo končni produkt želeli pripraviti po sintezni poti, ki vključuje zaščito piridina z oksidacijo, metiliranje in nato odščito piridinske zaščitne skupine. Po zamišljeni sintezni poti smo uspeli pridobiti željen ligand, vendar z nizkim celokupnim izkoristkom (32%). Z metilirano triazolijevo soljo smo nato poskusili pripraviti paladijev kompleks. Pridobili smo ugodne rezultate masne spektrometrije, ki je nakazovala nastanek paladijevega kompleksa z dvema vezanima ligandom na en paladijev center, vendar so bili NMR spektri istih produktov preveč kompleksni, da bi lahko z gotovostjo predlagali strukturo nastalega kompleksa. Iz različnih mešanic topil in z anionsko izmenjavo smo poskusili pridobiti kristal za določitev kristalne strukture, vendar neuspešno. Arilirane triazolijeve soli nismo pripravili iz istega prekurzorja kot metilirano, ampak smo pri tej sintezni poti najprej z ''klik'' reakcijo sintetizirali 1-fenil-5-(piridin-2-il)-1H-1,2,3-triazol, ki smo ga nato arilirali. Uspešno smo sintetizirali ariliran ligand, ki smo ga nato poskušali vezati na paladij. Ponovno smo pridobili ugodne rezultate masne spektrometrije, vendar kljub vrsti različnih uporabljenih topil za kristalizacijo in anionske izmenjave nismo uspeli pridobiti kristalne strukture ali NMR spektrov, iz katerih bi lahko z gotovostjo določili strukturo kompleksa.

Keywords

organska sinteza;N-heterociklični karbeni;triazolijeve soli;ligandi;paladijevi kompleksi;'klik' reakcija;alkiliranje;ariliranje;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [M. Žnidarič]
UDC: 547.79:546.98(043.2)
COBISS: 38318595 Link will open in a new window
Views: 409
Downloads: 93
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Other data

Secondary language: English
Secondary title: Synthesis of selected pyridyl-triazoles
Secondary abstract: The goal of this master thesis was the synthesis of selected triazolium salts, that would be functionalized with two pyridyl substituents, as potential ligands for complexes of palladium and other transition metals. We have successfully synthesized two such triazolium salts. The framework of both is 1,4-di(pyridine-2-yl)-1H-1,2,3-triazolium salt, which in one case is methylated at position 3, and arylated in other. The literature pathway for methylated compound uses 1,4-di(pyridine-2-yl)-1H-1,2,3-triazole as starting precursor that is methylated, however, majority of methylation occurs on pyridine (75%), and only 25% of the desired product is formed. We synthesized the starting 1,4-di(pyridine-2-yl)-1H-1,2,3-triazole with ‘click’ reaction between 2-azydopyridine and 2-ethynilpyridine. We tested three different copper catalysts for this transformation and optimized the reaction conditions. We wanted to synthesize the final product from 1,4-di(pyridine-2-yl)-1H-1,2,3-triazole with a synthetic pathway that includes the protection of pyridine with oxidation, methylation and deprotection of the N-oxide. We have managed to obtain the desired ligand, but with low overall yield (32%). We attempted the synthesis of the palladium complex with methylated triazolium salt. We have managed to obtain encouraging results with mass spectrometry, which indicated desired palladium complex formation with two bonded ligands, but the NMR spectra of the same products were too complex to definitely describe the structure of the complex. We have tried to obtain suitable crystals for diffraction analysis, but were unsuccessful. Arylated triazolium salt was prepared from 1-phenyl-5-(pyridine-2-yl)-1H-1,2,3-triazole, which we synthesized with ‘click’ reaction, and arylated subsequently. We have successfully synthesized the arylated triazolium salt, which we then tried to coordinate to palladium. We again obtained encouraging mass spectroscopy results, which indicated desired palladium complex formation with two bonded ligands, but although we tried several solvents and anion exchange, we did not manage to obtain crystal structure or NMR spectra from which we could inconclusively determine the structure of the complex.
Secondary keywords: triazolium salts;ligands;palladium complexes;'click' reaction;alkylation;arylation;
Type (COBISS): Master's thesis/paper
Study programme: 1000375
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemija
Pages: 70 str.
ID: 12078849