629-27-6Relevant articles and documents
HETEROGENOUS PHASE TRANSFER CATALYSTS. 1. SYNTHESIS AND CATALYTIC PROPERTIES OF POLYMERIC CROWN -ETHERS ON INORGANIC SUPPORTS
Loktev, V. F.,Morozova, I. Yu.,Tashmukhamedova, A. K.,Likholobov, V. A.
, p. 1128 - 1132 (1990)
A number of new heterogeneous phase transfer catalysts based on polymeric dibenzo-crown-ethers supported on the carbonaceous material "Sibunite", ultrafine diamonds, or silica gel are synthesized.The activity of several of the catalysts for the reaction of 1-bromooctane with KI is higher than that of previously known analogs.The catalytic effect depends on the support, linker, and solvent.
Aggregation behavior of sodium 3-(octyloxy)-4-nitrobenzoate in aqueous solution
Soto, Victor H.,Vázquez-Tato, M. Pilar,Meijide, Francisco,Alvarado, María José,Seijas, Julio A.,De Frutos, Santiago,Lomonte, Bruno,Vázquez Tato, José
, p. 19407 - 19414 (2018)
Ester 3-(octanoyloxy)-4-nitrobenzoic acid is a standard for the assay of the activity of phospholipase enzymes (the main toxins involved in tissue-damaging after snake bites). Because of its amphiphilic nature, it probably behaves as a surfactant but the instability of the ester bond prevents its characterization. Its ether analogue, 3-(octyloxy)-4-nitrobenzoic acid, is also an interesting compound as it is an inhibitor of the phospholipase activity and can be accepted as a model of the ester derivative. Its sodium salt, stable at basic pH, was studied by surface tension measurements, isothermal titration calorimetry, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The aggregation number, fraction of bound counterions, critical micelle concentration and thermodynamic parameters involved in demicellization were obtained. The positive value for the change in the heat capacity for demicellization indicates that a larger hydrophobic surface area of each monomer is exposed to a hydrophilic environment after dissociation. Semiempirical calculations are in agreement with DLS and TEM measurements. For several carboxylate surfactants, the plot of enthalpy vs. entropy is linear. Although the slope has been named the compensation temperature, Tc, it merely is an experimental temperature without any extra-thermodynamic meaning.
Cooperation between catalytic sites on a bicipital supported phosphonium phase-transfer catalyst
Clark, James H.,Tavener, Stewart J.,Barlow, Simon J.
, p. 2429 - 2430 (1996)
A novel bicipital tetraarylphosphonium salt grafted to silica gel is prepared and characterised, and gives unusually high catalytic rate enhancements in some nucleophilic substitution reactions, which suggest cooperation between the neighbouring phosphonium centres.
Radical induced disproportionation of alcohols assisted by iodide under acidic conditions
Huang, Yang,Jiang, Haiwei,Li, Teng,Peng, Yang,Rong, Nianxin,Shi, Hexian,Yang, Weiran
supporting information, p. 8108 - 8115 (2021/10/29)
The disproportionation of alcohols without an additional reductant and oxidant to simultaneously form alkanes and aldehydes/ketones represents an atom-economical transformation. However, only limited methodologies have been reported, and they suffer from a narrow substrate scope or harsh reaction conditions. Herein, we report that alcohol disproportionation can proceed with high efficiency catalyzed by iodide under acidic conditions. This method exhibits high functional group tolerance including aryl alcohol derivatives with both electron-withdrawing and electron-donating groups, furan ring alcohol derivatives, allyl alcohol derivatives, and dihydric alcohols. Under the optimized reaction conditions, a 49% yield of 5-methyl furfural and a 49% yield of 2,5-diformylfuran were obtained simultaneously from 5-hydroxymethylfurfural. An initial mechanistic study suggested that the hydrogen transfer during this redox disproportionation occurred through the inter-transformation of HI and I2. Radical intermediates were involved during this reaction.
A rings-in-pores net: Crown ether-based covalent organic frameworks for phase-transfer catalysis
Guo, Wen-Di,Hu, Bingwen,Jiang, Wei-Ling,Lou, Xiaobing,Ma, De-Li,Qi, Qiao-Yan,Shen, Ji-Chuang,Shen, Ming,Yang, Hai-Bo,Zhao, Xin
supporting information, p. 595 - 598 (2020/01/29)
We herein present a new family of crown ether-based covalent organic frameworks (CE-COFs) for the first time. The CE-COFs show excellent phase-transfer catalytic performance in various nucleophilic substitution reactions.