Utjecaj supstituenata na nukleofilnost purinskih baza

master's thesis

• Title (english): The influence of substituents on the nucleophilicity of purine bases
• Author: Marin Simić
• Mentor: Valerije Vrček (mentor)
• Committee member: Valerije Vrček (predsjednik povjerenstva)
• Committee member: Tin Weitner (član povjerenstva)
• Committee member: Davor Šakić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of organic chemistry); Zagreb
• Defense date and country: 2023-06-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Kvantno-kemijskim metodama izračunate su kondenzirane Fukui funkcije za purin, adenin i derivate
adenina, te je provedena usporedba s prethodno poznatim eksperimentalnim rezultatima konjugacije
ferocenoil-klorida na purin i njegove derivate. SN2-slična supstitucijska reakcija između ferocenoilklorida i aniona adenina je regioselektivan proces u kojem omjer produkata (N7/N9-ferocenoil
izomera) ovisi o steričkim svojstvima supstituenta na N6-položaju. Veliki, razgranati supstituenti na
N6-atomu mogu ometati reakciju na N7-položaju, sprječavajući pristup elektrofila. Kao posljedica
toga, smanjuje se udio N7-produkta, tj. raste udio N9-ferocenoil regioizomera. U slučaju kad je
sterički učinak zanemariv, kao npr. kod purina, prevladava elektronski učinak N6-supstituenta, što
je potkrijepljeno izračunima kondenziranih Fukui funkcija. Svi izračuni pokazuju da je atom N7
nukleofilniji od N9-atoma u svim purinskim derivatima.

Abstract (english)

Condensed Fukui functions for purine, adenine and adenine derivatives were calculated using
quantum chemical methods and a comparison was made with previously known experimental results
of ferrocenyl chloride conjugation to purine and its derivatives. The SN2-like substitution reaction
between ferrocenoyl chloride and adenine anion is a regioselective process in which the product
ratio (N7/N9-ferrocenoyl isomer) depends on the steric properties of the substituent at the N6-
position. Large, bulky substituents at the N6-atom can hinder the reaction at the N7-position,
preventing access of an electrophile. As a consequence, the proportion of N7-product decreases, i.e.
the proportion of N9-ferrocenoyl regioisomer increases. In the case when the steric effect is
negligible, such as for purines, the electronic effect of the N6-substituent prevails, which is
supported by calculations of condensed Fukui functions. All calculations show that the N7 atom is
more nucleophilic than the N9 atom in all purine derivatives.

• Keywords: adenin; ferocen; NMR spektroskopija; računalna kemija
• Keywords (english): adenine; ferrocene; NMR spectroscopy; computational chemistry
• Language: croatian
• URN:NBN: urn:nbn:hr:163:587344
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-01-04 16:02:10