70969-20-9Relevant academic research and scientific papers
Neighboring Group Participation by Carbonyl Oxygen in Nucleophilic Substitution. Hydrolyses of methyl(p-nitrophenyl)sulfonium Tetrafluoroborate
Irie, Tadashi,Tanida, Hiroshi
, p. 1795 - 1800 (1980)
Evidence was obtained for participation of a hydration equilibrium of a carbonyl compound in an SN2 reaction.Hydrolysis of methyl(p-nitrophenyl)sulfonium tetrafluoroborate (10) in aqueous buffer medium afforded in quantitative yield an alcohol of retained structure, (9-oxobenzonorbornen-exo-2-yl)methanol (9), as a result of nucleophilic attack of water at the sterically more hindered methylene carbon α to the sulfonium sulfur.In contrast, the same reactions of the endo-2-yl epimer (11) and isobutylmethyl(p-nitrophenyl)sulfonium perchlorate (15, a model compound) occurred at the less hindered methyl carbon, entirely for 11 and predominantly for 15.The overall rate law for the hydrolysis of 10 is suggested to be rate = (kH2O + kH+> + kOH-> + kHB + kB + kBT,OHT->).All the coefficients k determined were in almost the same order of magnitude as the corresponding k's recently reported for the hydrolysis of the anti-9-hydroxybenzonorbornene derivative (4), which involves participation by hydroxyl oxygen.When kH2O and kOH were compared with the corresponding rates of another model, dimethyl(p-nitrophenyl)sulfonium perchlorate (14), the relative reactivities were calculated as 240 and 106, respectively, and the effective molarity (EM) was calculated as 1.3*104 M.
