Ciklički gvanidini kao kokatalizatori u aldolnoj reakciji

master's thesis

• Title (english): Cyclic guanidines as cocatalyst in aldol reaction
• Author: Monika Marijanović
• Mentor: Zoran Glasovac (mentor)
• Committee member: Ines Primožič (predsjednik povjerenstva)
• Committee member: Iva Juranović Cindrić (član povjerenstva)
• Committee member: Željka Soldin (član povjerenstva)
• Committee member: Željka Car (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2023-02-14, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

U ovom radu pripravljene su jodidne soli gvanidina u svrhu ispitivanja njihove kokatalitičke
aktivnosti u reakciji aldolne kondenzacije cikloheksanona i 4-klorbenzaldehida uz katalizator
L-prolin. Odabrani aciklički i ciklički gvanidinski derivati razlikuju se prema usmjerenosti
NH veza, steričkim utjecajima i supstituentima. Dobivenim su spojevima ispitana kiselobazna svojstva u acetonitrilu uz referentni spoj poznate bazičnosti UV titracijom i NMR
spektroskopijom. Spektrometrijom masa provedeno je kinetičko mjerenje relativnih afiniteta
vezanja jodida fragmentacijom jodidom premoštenog dimera ispitivanog i referentnog
gvanidina. Omjer dijastereomera produkata aldolne kondenzacije nastalog kao rezultat
kokatalitičke aktivnosti gvanidina praćen je HPLC i NMR tehnikom. Pokazano je da
dijastereomerni omjer produkata ovisi o kiselo-baznim svojstvima gvanidina, usmjerenosti
NH veza i stvaranju međumolekulske i unutarmolekulske vodikove veze. Navedeni čimbenici
utječu na stabilnost katalitičkog kompleksa među gvanidinom, supstratom i L-prolinom te
time imaju izravan utjecaj na konačan ishod reakcije.

Abstract (english)

In this master thesis, iodide salts of guanidine were prepared for the purpose of testing their
cocatalytic activity in the aldol condensation of cyclohexanone and 4-chlorobenzaldehyde
with L-proline as catalyst. Acyclic and cyclic guanidine derivatives differ by the orientation
of NH bonds, steric effect and substituents. Acid-base properties of the obtained compounds
were determined in acetonitrile with a reference compound of known basicity using UV
titration and NMR spectroscopy. Mass spectrometry was used to measure the relative affinity
of iodide binding by fragmentation of the iodide-bound dimer of the tested and reference
guanidine. Diastereomeric ratio of the aldol condensation products, as a result of cocatalytic
activity of guanidines, was monitored by HPLC and NMR techniques. It was shown that the
diastereomeric ratio of the products depends on the acid-base properties, orientation of NH
bonds in guanidine and formation of intramolecular and intermolecular hydrogen bonds. The
mentioned factors influence the stability of the catalytic complex between guanidine,
substrate and L-proline and thus have a direct effect on the final outcome of the reaction.

• Keywords: aldolna kondenzacija; dijastereomerni omjer; gvanidin; kokatalizator; sinteza
• Keywords (english): aldol condensation; cocatalyst; diastereomeric ratio; guanidine; synthesis
• Language: croatian
• URN:NBN: urn:nbn:hr:217:588401
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-03-16 13:03:51