21251-12-7Relevant articles and documents
Micellization of alkyltriphenylphosphonium bromides in ethylene glycol and diethylene glycol + water mixtures: Thermodynamic and kinetic investigation
Kolay, Sancheeta,Ghosh, Kallol K.,MacDonald, Amy,Moulins, Jonathan,Palepu, Rama M.
, p. 59 - 72 (2008)
The thermodynamics of micellization and other micellar properties of alkyl- (C10-, C12-, C14- and C16-) triphenylphosphonium bromides in water + ethylene glycol (EG) (0 to 30% v/v) mixtures over a temperature range of 298 to 318 K and cetyltriphenylphosphonium bromide in water + diethylene glycol (DEG) mixtures (0 to 30% v/v) at 298 K have been studied conductometrically. In all cases, an increase in the percentage of co-solvent results in an increase in the cmc values. On the basis of these results, the thermodynamic parameters, the Gibbs energy (ΔG mo), enthalpy (ΔHmo ) and entropy (ΔSmo ) of micellization have been evaluated. In addition to the conductivity measurements, kinetic experiments have also been done to determine the dependence of observed rate constant for the nucleophilic substitution reaction of p-nitrophenyl acetate and benzohydroxamate ions in the presence of the surfactant cetyltriphenylphosphonium bromide with a varying concentration of EG and DEG ranging from 0 to 50% v/v at pH=7.9 and 300 K. All of the reactions followed pseudo-first-order kinetics. An increase in the surfactant concentration results in an increase in the reaction rate and for a given surfactant concentration, the rate constant decreases as the concentration of co-solvent in the mixture increases. The kinetic micellar effects have been explained by using the pseudophase model. The thermodynamic and structural changes originating from the presence of solvents control the micellar kinetic effects.
Synergistic Dual Directing Groups-Enabled Diastereoselective C-H Cyclopropylation via Rh(III)-Catalyzed Couplings with Cyclopropenyl Alcohols
Wu, Min,Lin, Shuang,Zhu, Guoxun,Sun, Ming,Zhou, Zhi,Gao, Hui,Yi, Wei
supporting information, (2020/02/25)
By using a synergistic dual directing group-assisted C-H activation strategy and simply modifying the reaction conditions, we realized a robust and general Cp*Rh(III)-catalyzed C-H cyclopropylation of N-acetoxybenzamides with cyclopropenyl alcohols, provi
Rhodium(iii)-catalyzed formal oxidative [4 + 1] cycloaddition of benzohydroxamic acids and α-diazoesters. A facile synthesis of functionalized benzolactams
Lam, Hon-Wah,Man, Ka-Yi,Chan, Wai-Wing,Zhou, Zhongyuan,Yu, Wing-Yiu
, p. 4112 - 4116 (2014/06/10)
A Rh(iii)-catalyzed oxidative [4 + 1] cycloaddition of benzohydroxamic acids and α-diazoesters is achieved to afford benzolactams in up to 93% yields. With the N-OAc amido moiety as a directing group, the ortho-C-H is selectively functionalized and the catalytic reaction exhibits excellent tolerance to different functional substituents. A notable rhodacyclic complex is isolated and structurally characterized, suggesting that C-H/N-H cyclometallation is a key step in the catalytic cycle. This journal is the Partner Organisations 2014.
