68240-81-3Relevant academic research and scientific papers
Solvolytic reactivity of pyridinium ions
Juric, Sandra,Kronja, Olga
, p. 314 - 319 (2015)
The leaving group abilities of pyridine, 4-methylpyridine, and 4-chloropyridine in SN1 solvolytic reactions have been determined by analyzing the rate constants of X,Y-substituted benzhydrylpyridinium salts obtained in various solvents. By applying the linear free energy relationship equation, log k = sf (Ef + Nf), the nucleofuge specific parameters of 4-substituted pyridine have been extracted. Because of solvation in the reactant ground state, the reactivity (nucleofugality, Nf) of a given pyridine decreases as the polarity of the solvent increases. High slope parameters (sf > 1) may be due to the spread of the energy levels of the benzhydrylium ion/pyridine pair intermediates in comparison to benzhydrylium ion/chloride pairs (sf ≈ 1). Because of slow heterolysis step of pyridinium salts in various solvents, some are stable under normal conditions.
Why are vinyl cations sluggish electrophiles?
Byrne, Peter A.,Kobayashi, Shinjiro,Würthwein, Ernst-Urich,Ammer, Johannes,Mayr, Herbert
supporting information, p. 1499 - 1511 (2017/02/10)
The kinetics of the reactions of the vinyl cations 2 [Ph2C=C+-(4-MeO-C6H4)] and 3 [Me2C=C+-(4-MeO-C6H4)] (generated by laser flash photolysis) with diverse nucleophile
SN1 reactions with inverse rate profiles
Denegri, Bernard,Minegishi, Shinya,Kronja, Olga,Mayr, Herbert
, p. 2302 - 2305 (2007/10/03)
Carbocations may accumulate during solvolysis reactions! The fact that fast ionization followed by slow trapping of the carbocation R+ is a characteristic pattern of many solvolysis reactions requires that the generally accepted energy profiles of these reactions be revised.
An Approach towards Identification of Product Precursors in the Solvolyses of Diarylmethyl p-Nitrobenzoates in Ethanol-Water Solvents
McLennan, Duncan J.,Martin, Peter L.
, p. 1099 - 1106 (2007/10/02)
The product ratios, ether:alcohol, for the solvolyses of the title compounds in ethanol-water solvent mixtures have been measured, and have been compared with ratios of the same products generated from the reactions of the corresponding diaryldiazomethanes in the same solvents.The ratios are similar although not always identical, and disparities are ascribed to solvation differences.The question of 'selectivities' of intermediates towards ethanol and water is addressed, and it is concluded that product ratios can be used as selectivity measures only when a single intermediate yields stable products.The present results thus throw little light on the reality or otherwise of stability-selectivity relationships in the present series.Internal return is suggested as an important component in the unassisted solvolysis of the esters.
