Further Evidence for the Triplet Mechanism in the Photosubstitution of Nitroaryl Ethers in Alkaline Medium.
作者:João Baptista Sargi Bonilha、Antonio Claudio Tedesco、Lazaro Cicero Nogueira、Maria Teresa Ribeiro Silva Diamantino、Júlio Cesar Carreiro
DOI:10.1016/s0040-4020(01)89887-2
日期:1993.4
Mechanistic studies show that nitroaryl ethers (3-nitroanisole, 3-nitrophenetole, n-butyl 3-nitrophenyl ether, 2-chloro-5-nitroanisole, 2-bromo-5-nitroanisole and 3,5-dinitro anisole) undergo nucleophilic aromatic photosubstitution with hydroxide ions through an SN23Ar* mechanism. An investigation of the quenching of exited states of nitroanyl ethers by bromide and thiosulfate ions in aqueous solutions
机理研究表明,硝基芳基醚(3-硝基苯甲醚,3-硝基苯酚,正丁基3-硝基苯醚,2-氯-5-硝基苯甲醚,2-溴-5-硝基苯甲醚和3,5-二硝基苯甲醚)经历亲核芳香性光解。通过S N 2 3 Ar *机理与氢氧根离子发生反应。据报道,研究了水溶液中溴化物和硫代硫酸根离子对硝基戊基醚的出口态的猝灭,这为提出的S N 2 3 Ar *机理提供了支持。
[EN] NOVEL CURING AGENTS AND DEGRADABLE POLYMERS AND COMPOSITES BASED THEREON<br/>[FR] NOUVEAUX AGENTS DURCISSEURS ET POLYMÈRES ET COMPOSITES DÉGRADABLES À BASE DE CES DERNIERS
申请人:ADESSO ADVANCED MATERIALS WUXI CO LTD
公开号:WO2014169847A1
公开(公告)日:2014-10-23
The present invention provides,among others,compounds of Formula (I)or a salt thereof,methods for making these compounds,degradable polymers and reinforced composites made therefrom,and methods for degrading and/or recycling the degradable polymers and reinforced composites.
Surfactant-mediated solvent-free dealkylative cleavage of ethers and esters and trans-alkylation under neutral conditions
作者:Apurba Bhattacharya、Nitin C. Patel、Tomas Vasques、Ritesh Tichkule、Gaurang Parmar、Jiejun Wu
DOI:10.1016/j.tetlet.2005.11.048
日期:2006.1
A simple, surfactant-mediated, one-pot, solvent-free dealkylative cleavage of aryl ethers and esters followed by subsequent optional trans-alkylation under essentially neutral conditions has been developed.
α-Cyclodextrin (α-CD) and 6-O-α-d-glucopyranosyl-β-cyclodextrin (G1-β-CD) affected the rates of phenol release from a few dimethyl(nitrophenyl) phosphates and the corresponding thiophosphates in aqueous alkaline solutions. Curve-fitting analysis of changes in the rate constants with CD concentrations showed that both α-CD and G1-β-CD form not only 1:1 but also 2:1 (host:guest) complexes with the phosphates and thiophosphates. In 1:1 complexes, phenol release from the phosphates was mostly accelerated, and that from the thiophosphates was decelerated. In 2:1 complexes, the reactions both of the phosphates and thiophosphates were strongly retarded. Binding constants and rate constants determined showed significant host and substrate specificities.
Enthalpy-Entropy Correlations in Reactions of Aryl Benzoates with Potassium Aryloxides in Dimethylformamide
作者:Irina A. Khalfina、Vladislav M. Vlasov
DOI:10.1002/kin.20763
日期:2013.4
concluded that the reactions of aryl benzoates PhCO2C6H4Y with potassium aryloxides in DMF proceed via a four‐step mechanism. The large ρ0(Y) and ρXY values at 25°C obtained for the reactions of 1–3 with potassium aryloxides with an electron‐donating substituent refer to the rate‐determining formation of the spiro‐σ‐complex. The Hammettplots for the reactions of 1 and 2 exhibit a downward curvature, causing
钾芳氧化物XC的相对反应性的温度依赖性6 ħ 4 ö - ķ +朝向4-硝基苯基(1),3-硝基苯基(2),4-氯苯基(3),和苯基(4)在二甲基甲酰胺苯甲酸酯(DMF)使用竞争反应技术进行了研究。1与4-氰基苯酚钾,2与3-溴苯酚钾,3与3-溴苯酚,4-溴苯酚和未取代的苯酚钾的反应的速率常数k X,4在25°C下用4-甲氧基钾和3-甲基苯酚钾测定。相对速率常数k X / k H(3-Me)与竞争性反应的活化参数差异(∆∆Н ≠和∆∆ S ≠)的相关分析表明存在六个等速序列。我们研究了X对每个等动力学系列的活化参数的取代基效应,并得出结论,苯甲酸芳基酯PhCO 2 C 6 H 4 Y与芳基氧化钾在DMF中的反应通过四步机理进行。大ρ 0(Y)和ρ XY1–3与带有给电子取代基的芳基氧化钾反应在25°C下获得的值是确定螺-σ-络合物形成速率的速率。1和2反应的Hammett图表现出向下的曲率