magistrsko delo
Povzetek
Namen magistrskega dela je bila optimizacija sinteze paladijevega kompleksa z
dvema Py-tzNHC ligandoma. Sintezo smo pričeli s pripravo izhodnega azida, ki mu je
sledila 'klik' reakcija s terminalnim acetilenom do ustreznega triazola. V naslednji stopnji
smo tvorili ustrezen N-oksid. In sicer z oksidacijo piridinskega dušika v dvofaznem sistemu
kloroform-vodna raztopina. Kombinacija vodikovega peroksida in ocetne kisline se v
prisotnosti žveplove(VI) kisline in situ pretvori v peroksiocetno kislino, ki služi kot
oksidant pri sami reakciji. Sledilo je metiliranje triazolnega obroča na poziciji N3. Poleg
dušika na triazolnem obroču se je metiliral tudi kisik na piridinskem dušiku, zato smo v
naslednjem koraku z redukcijo s cinkom v prisotnosti NH4BF4 cepili vez N–O in kot
produkt dobili s piridinom funkcionaliziran triazolijev tetrafluoroborat, ki služi kot ligand
pri pripravi paladijevega kompleksa. Kot vir paladija za tvorbo želenega kompleksa smo
uporabili PdCl2, kot bazo pa Cs2CO3. Pri tem se je en ligand vezal bidentatno, drugi pa le
monodentatno. Da smo zagotovili bidentatno vezavo tudi drugega liganda, smo morali
izvesti odstranitev kloridnega iona iz kovinskega centra z uporabo AgBF4. Tako smo
uspešno sintetizirali mezoionski paladijev(II) kompleks, ki je uporaben v številnih
reakcijah spajanja.
Ključne besede
paladij;paladijevi(II) kompleksi;ligandi;N-oksidi;piridin;oksidacija;redukcija;1,2,3-triazolijeve soli;N-heterociklični karbeni;paladijevi NHC kompleksi;magistrska dela;
Podatki
Jezik: |
Slovenski jezik |
Leto izida: |
2021 |
Tipologija: |
2.09 - Magistrsko delo |
Organizacija: |
UL FKKT - Fakulteta za kemijo in kemijsko tehnologijo |
Založnik: |
[D. Zupančič] |
UDK: |
547.79:546.98(043.2) |
COBISS: |
55217155
|
Št. ogledov: |
298 |
Št. prenosov: |
71 |
Ocena: |
0 (0 glasov) |
Metapodatki: |
|
Ostali podatki
Sekundarni jezik: |
Angleški jezik |
Sekundarni naslov: |
Optimisation of synthesis of mesoionic palladium(II) complex |
Sekundarni povzetek: |
The main goal of master's thesis was the optimization of the synthesis of a planar
palladium complex, bearing two Py-tzNHC ligands. In the first step the starting azide was
formed, which reacted in a ‘click’ reaction with desired alkyne into the appropriated
triazole. In the next step pyridine nitrogen was oxidized into N-oxide using biphasic system
chloroform-water. Peroxyacetic acid was used as an oxidant, which was formed in situ
between hydrogen peroxide and acetic acid in the presence of catalytic amounts of
sulphuric(VI) acid. Oxidation was followed by methylation of the triazole ring at position
N3. In addition to the nitrogen at the triazole ring, pyridine N-oxide atom was also
methylated. N–O bond cleavage in the subsequent step was achieved by using activated
zinc in the presence of NH4BF4 to afford a pyridine-functionalized triazolium
tetrafluoroborate, which served as a ligand in the preparation of the desired mesoionic
palladium complex. For the preparation of targeted complex, PdCl2 was chosen as the
palladium source in the presence of Cs2CO3 as a base. One ligand coordinated in a
bidentate, and the other in monodentate fashion. To achieve bidentate coordination of both
ligands, the abstraction of chloride ion from the metal centre had to be performed, which
was achieved by using AgBF4. With that the desired mesoionic palladium(II) complex,
broadly used as a versatile catalyst for various cross-coupling reactions, was successfully
synthesized under optimized reaction conditions. |
Sekundarne ključne besede: |
N-oxide;oxidation;reduction;palladium; |
Vrsta dela (COBISS): |
Magistrsko delo/naloga |
Študijski program: |
1000375 |
Komentar na gradivo: |
Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemija |
Strani: |
53 str. |
ID: |
12649791 |