102073-39-2Relevant academic research and scientific papers
Rates and Equilibria of the Methoxide Attachment to 2,6-Di-tert-butyl-4-arylthiopyrylium Cations. Can Ion Pair Formation Be Rate Determining in Anion-Cation Combination Reactions?
Vona, M. L. Di,Doddi, G.,Ercolani, G.,Illuminati, G.
, p. 3409 - 3415 (1986)
The complete set of kinetic and equilibrium constants for the methoxide attachment to a series of 2,6-di-tert-butyl-arylthiopyrylium cations (aryl= X-C6H4 with X= p-NO2, m-Cl, p-Cl, H, p-Me, p-OMe, p-NMe2) has been obtained in MeOH at 25 deg C.The reactio
1H Nuclear Magnetic Resonance Study of Methoxide Addition to Pyrylium and Thiopyrylium Cations; Heteroatom and Substituent Effects
Doddi, Giancarlo,Ercolani, Gianfranco
, p. 271 - 276 (2007/10/02)
Methoxide addition to pyrylium and thiopyrylium salts with various α-substituents (Ph or tBu) and γ-substituents (H, Me, tBu, Et3C, Ph or MeO) in methanol at -40 and 25 deg C has been studied by 1H n.m.r.The composition of the product mixtures, kinetically controlled at -40 deg C and thermodynamically controlled at 25 deg C, gives information on the factors affecting positional selectivity and the relative thermodynamic stability of the addition products (the 2H- and 4H-adduct).The methyl-substituted substrates also undergo deprotonation, to yield the corresponding anhydro-bases.Analysis of heteroatom and substituent effects on the rean course emphasizes the role of polar and steric interactions, and sheds light on the structures of the transition states.
