Naslov
Selectivity of Stabilized Benzhydrylium Ions

Autori
Denegri, Bernard ; Matić, Mirela ; Kronja, Olga

Izvornik
European journal of organic chemistry (1434-193X) 803 (2010), 8; 1440-1444

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

Ključne riječi
selectivity; stabilized benzhydrylium ions; methyl and phenyl carbonates; microsolvation

Sažetak
Methyl carbonates (1–4–OCO2Me) and phenyl carbonates (2–4–OCO2Ph) were subjected to solvolysis in the series of aqueous ethanol, the product ratios were determined and the selectivities (kE/kW) of the corresponding stabilized benzhydrylium ions 1–4 were calculated. The individual rate constants for ethanolysis (kE) and hydrolysis (kW) have been calculated. Ethanolysis proceeds via earlier more carbocation-like transition state than hydrolysis. Due to more important solvation, kE decreases slower than kW if the fraction of the water in the binary solvent increases, which net effect is pronounced dependence of the selectivity on the solvent polarity. The selectivities of less stable carbocations 5–8 are reduced and influenced by the leaving group because of pairing and bending of the log k vs. E plot.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA