Naslov
A DFT/PCM-based methodology for predicting solvolytic reactivities of organic carbonates

Autori
Matić, Mirela ; Denegri, Bernard

Izvornik
Organic & biomolecular chemistry (1477-0520) 16 (2018), 25; 4665-4674

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Carbonate, bicarbonate, nucleofugality, solvolysis, DFT, M06-2X, IEFPCM, SMD

Sažetak
The possibility of employing quantum mechanical computations to predict solvolysis rates of benzhydryl aryl/alkyl (Ar/R) carbonates and to determine nucleofugalities of various Ar/R carbonate leaving groups in terms of Nf values is examined. Since unassisted SN1 transition states of neutral substrates cannot be optimized by using implicit solvation models, a model reaction that includes anchimerically assisted heterolysis of 2-oxyethyl Ar/R carbonates is utilized to determine the relative reactivities of both benzhydryl Ar/R carbonate substrates and Ar/R carbonate leaving groups. Very good linear correlations have been obtained between activation free energies of the model reaction, calculated by using the M06-2X method in conjunction with the IEFPCM solvation model, and activation free energies in the literature for solvolysis of the corresponding benzhydryl Ar/R carbonates in a given solvent. The slopes of close to unity demonstrate that calculated and measured relative reactivities of the Ar/R carbonate leaving groups are practically the same. Very good agreement between experiment and theory has enabled extending the nucleofugality (Nf) scale established by Mayr and co-workers (Acc. Chem. Res., 2010, 43, 1537–1549) with numerous new Ar/R carbonate leaving groups.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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