94670-31-2Relevant articles and documents
Iodine-catalyzed transformation of aryl-substituted alcohols under solvent-free and highly concentrated reaction conditions
Jereb, Marjan,Vra?i?, Dejan
, p. 747 - 762 (2018/01/17)
Iodine-catalyzed transformations of alcohols under solvent-free reaction conditions (SFRC) and under highly concentrated reaction conditions (HCRC) in the presence of various solvents were studied in order to gain insight into the behavior of the reaction intermediates under these conditions. Dimerization, dehydration and substitution were the three types of transformations observed with benzylic alcohols. Dimerization and substitution reactions were predominant in the case of primary- and secondary alcohols, whereas dehydration prevailed in the case of tertiary alcohols. The relative reactivity of substituted 1-phenylethanols in I2-catalyzed dimerization under SFRC provided a good Hammett plot ρ+ = -2.8 (r2 = 0.98), suggesting the presence of electron-deficient intermediates with a certain degree of developed charge in the rate-determining step.
LASER FLASH PHOTOLYSIS OBSERVATION OF THE 1-p-METHOXYPHENYLVINYL CATION BY PHOTOPROTONATION OF p-METHOXYPHENYLACETYLENE. COMPARISON WITH THE 1-p-METHOXYPHENETHYL CATION.
McClelland, Robert A.,Cozens, Frances,Steenken, Steen
, p. 2821 - 2824 (2007/10/02)
Photolysis of p-methoxyphenylacetylene in trifluoroethanol results in transient 1-p-methpoxyphenylvinyl cation 7 which has been detected by laser flash photolysis (λ = 248 nm).This cation shows remarkably similar behaviour to the 1-p-methoxyphenethyl cati
Equilibrium Constants for the Interconversion of Substituted 1-Phenylethyl Alcohols and Ethers. A Measurement of Intramolecular Electrostatic Interactions
Rothenberg, Marc E.,Richard, John P.,Jencks, William P.
, p. 1340 - 1346 (2007/10/02)
Equilibrium constants for the reactions of ring-substituted 1-phenylethyl alcohols with a series of aliphatic alcohols of pKa 12.4-16 to form the corresponding ethers, and for interconversion of the ethers, have been determined in 50:45:5 HOH/CF3CH2OH/ROH (v/v/v), μ = 0.5 (NaCIO4), at 25 deg C.Formation of ethers from the alcohols is favorable, with values of K = 3-74; replacement of water by methanol is favored by factors of 50-74.Equilibrium constants increase with increasing pKa of the alcohol with values of βeq = δlog K/δpKROH in the range 0.17-0.27.This is attributed to hydrogen bonding of the alcohol to the solvent and to an electrostatic interaction between substituents on the alcohol and the aryl group.The contribution from hydrogen bonding to the solvent is estimated to be β = 0.17; for 90percent HOH it is 0.25.An increase in βeq with electron-withdrawing substituents on the benzene ring and a complementary increase in ρeq with electron-donating substituents on ROH are described by an electrostatic interaction coefficient τ = δβeq/δ? = δρeq/δpKROH = 0.10 +/- 0.01.No change in τ for dipole-dipole interactions was observed with increasing water concentration in the range 50-90percent (v/v).The electrostatic interactions that are described by τ can cause changes in structure-reactivity parameters, such as ρ or β, in the absence of changes in transition-state structure.
