Naslov
Reaction mechanism of transferrocenoylation of purines. A DFT study

Autori
Toma, Mateja ; Božičević, Lucija ; Šakić, Davor ; Vrček, Valerije

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Computational Chemistry Day 2019, Book of Abstracts / Babić, Darko - Zagreb : Prirodoslovno-matematički fakultet Sveučilišta u Zagrebu, 2019, 26-26

ISBN
978-953-6076-51-2

Skup
Computational Chemistry Day 2019

Mjesto i datum
Zagreb, Hrvatska, 11.05.2019

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
ferrocenoyl-purines, tranacylation, DFT

Sažetak
Ferrocenoyl-purines are organometallic derivatives combining redox-active and biogenic parts. In the reaction of ferrocenoyl chloride and purine anion, two isomers (N7 and N9) were formed, with the ratio depending on the C6-purine substituent. We found that each of the isomers (N7 and N9) in DMSO undergoes transacylation reaction with the ratio approaching to the equilibrium state. The mechanism of transacylation in ferrocenoylated purines (R = NH2, CH3, O-CH2Ph, NH-CH2Ph) starts with the nucleophilic attack of the sulfur atom of DMSO on the carbonyl group at the N7-(or N9) position, and follows the SN2-like mechanism. The reaction mechanism was explored by the use of DFT models. To locate stationary points (transition states and minima), we introduced two explicit molecules of DMSO by the stochastic procedure. The conformational analysis revealed the relative energy range of approximately 100 kJ/mol, which shows that searching for the optimal position of explicit solvent molecules is prone to large errors. Gibbs free energy barriers were calculated at the SMD-M06L/6-311+G(d, p)/SDD and SMD-B3LYP/6-31G(d)/SDD level. In the case of adenine (R = NH2), the introduction of the first explicit DMSO molecule sets the barrier to ΔG> 130 kJ/mol, but the second one lowers the energy close to the experimental value: ΔGexp≈104 kJ/mol, ΔGcalc≈108 kJ/mol (M06L/6-311+G(d, p)/SDD).

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Farmacija

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