110079-40-8Relevant academic research and scientific papers
The Reactions of Monoalkylthio- or Monoarylthio-Substituted Cyclopropenium Salt with Nitrogen Nucleophiles: Formation of Polyfunctionally Substituted Pyrroles or Pyrazoles
Yoshida, Hiroshi,Utsumi, Fumitaka,Suzuki, Hideki,Ito, Satoru,Sakashita, Shin-ichi,et al
, p. 698 - 702 (2007/10/02)
The reactions of monoalkylthio- or monoarylthio-substituted cyclopropenium salt (1) with a number of secondary amines were studied.The amines, such as N-methylaniline, yielded indenes, whereas N-alkyl- or N-arylbenzylamines gave 1-alkyl or 1-aryl-2-phenyl
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. XX. Secondary Isotope Effect on Kinetic Basicity of Amine Ligands in Boronate-Amine Complexes and Ammonium Salts
Toyota, Shinji,Oki, Michinori
, p. 2215 - 2220 (2007/10/02)
Secondary isotope effects on the kinetic basicity of amine ligands in boronate-amine complexes and ammonium salts were first determined by taking advantage of the rate constants of the dissociation of the amine ligands measured by the dynamic NMR method.The basicities of amine ligands are enhanced by the α-deuterations in the both compounds and the isotope effect caused by a deuterium is larger in the boronate complexes than the ammonium salts.These isotope effects are discussed on the basis of the inductive and steric effects.
Reactions of N-Chlorobenzylalkylamines with Sodium Methoxide in Methanol. Steric Effects in Elimination Reactions
Cho, Bong Rae,Maeng, Jun Ho,Yoon, Jong Chan,Kim, Tae Rin
, p. 4752 - 4756 (2007/10/02)
Reactions of N-chlorobenzylalkylamines in which the alkyl group is Me, Et, i-Pr, t-Bu, and sec-Bu with MeONa-MeOH have been investigated kinetically.The eliminations are quantitative and regiospecific, producing only benzylidenealkylamines.The reactions are first order in base and first order in substrate, and an E2 mechanism is evident.The relative rates of elimination at 25 deg C are 1/0.5/0.3/0.2/0.01 for Me/Et/i-Pr/sec-Bu/t-Bu alkyl substituents, respectively.The results are attributed to repulsive interaction between the alkyl group and the base in the transition state.Hammett ρ and kH/kD values decreased, but the ΔH(excit.) and ΔS(excit.) values increased with bulkier alkyl substituents.Changes in the transition-state parameters with the substrate steric effect are interpreted with variation in structure of the imine-forming transition states.
