Kinetics and Mechanism of the Anilinolysis of Aryl 4-Nitrophenyl Carbonates in Aqueous Ethanol
作者:Enrique A. Castro、Marcela Gazitúa、José G. Santos
DOI:10.1021/jo051168b
日期:2005.9.1
slopes for the two latter reactions are in accordance with those obtained in stepwise mechanism where breakdown to product of a zwitterionic tetrahedral intermediate is the rate-determining step. On the other hand, the β value for the reactions of BNPC is at the upper limit of those found for concerted mechanisms. The kinetic results for the reactions of anilines with BNPC correlates well with those
苯胺与4-硝基苯基,4-甲基苯基和4-氯苯基碳酸4-硝基苯酯(分别为BNPC,MPNPC和ClPNPC)的反应是在44 wt%的乙醇-水中于25.0°C下以离子强度进行动力学研究的0.2 M(KCl)。的曲线图ķ实测值VS [胺]是线性的,与所述斜坡(ķ Ñ)与pH值无关。布朗斯台德型图(log k N vs p K a苯胺的共轭酸的线性是线性的,对于苯胺与BNPC,MPNPC和ClPNPC的反应,斜率分别为β= 0.65、0.85和0.78。后两个反应的斜率值与在逐步机理中获得的斜率值一致,其中两性离子四面体中间体的分解是决定速率的步骤。另一方面,BNPC反应的β值处于协同机制发现的β值的上限。苯胺与BNPC反应的动力学结果与相同胺与4-甲基苯基和4-氯苯基2,4-二硝基苯基碳酸酯的协同反应的动力学结果密切相关:计算的log k N值的图(通过多次参数方程式)与实验对数k N值是线性的,
A phenacrylate scaffold for tunable thiol activation and release
作者:Rathinam K. Sankar、Rohan S. Kumbhare、Allimuthu T. Dharmaraja、Harinath Chakrapani
DOI:10.1039/c4cc07343f
日期:——
A scaffold for biological thiol mediated tunable activation and release of a cargo is reported.
Carbonyl Sulfide (COS) Donor Induced Protein Persulfidation Protects against Oxidative Stress
作者:Preeti Chauhan、Kavya Gupta、Govindan Ravikumar、Deepak K. Saini、Harinath Chakrapani
DOI:10.1002/asia.201901148
日期:2019.12.13
The emergence of hydrogensulfide (H2 S) as an important signalling molecule in redox biology with therapeutic potential has triggered interest in generating this molecule within cells. One strategy that has been proposed is to use carbonyl sulfide (COS) as a surrogate for hydrogensulfide. Small molecules that generate COS have been shown to produce hydrogensulfide in the presence of carbonic anhydrase
Visible-Light-Triggered Uncaging of Carbonyl Sulfide for Hydrogen Sulfide (H<sub>2</sub>S) Release
作者:Ajay Kumar Sharma、Mrutyunjay Nair、Preeti Chauhan、Kavya Gupta、Deepak K Saini、Harinath Chakrapani
DOI:10.1021/acs.orglett.7b02259
日期:2017.9.15
Generation of hydrogensulfide (H2S) is challenging and few methods are capable of localized delivery of this gas. Here, a boron dipyrromethene-based carbamothioate (BDP-H2S) that is uncaged by visible light of 470 nm to generate carbonyl sulfide (COS), which is rapidly hydrolyzed to H2S in the presence of carbonic anhydrase, a widely prevalent enzyme, is reported.
硫化氢(H 2 S)的产生是具有挑战性的,很少有方法能够局部输送这种气体。这里,基于二吡咯亚甲基硼carbamothioate(BDP-H 2 S)是由470nm的可见光出笼生成硫化羰(COS),其被迅速水解成H 2 S IN碳酸酐酶的存在下,一种广泛流行酶,据报道。
Anilinolysis of reactive aryl 2,4-dinitrophenyl carbonates: Kinetics and mechanism
作者:Enrique A. Castro、Claudia Domecq、José G. Santos
DOI:10.1002/kin.20544
日期:2011.4
at constant pH are linear, with slopes kN. The Brønsted plots (log kN vs. anilinium pKa) for the anilinolysis of 1–3 are linear, with slope (β) values of 0.52, 0.61, and 0.63, respectively. The values of these slopes and other considerations suggest that these reactions are ruled by a concerted mechanism. For these reactions, the kN values follow the reactivity sequence: 3 > 2 > 1. Namely, the reactivity
一系列苯胺与碳酸2,4-二硝基苯基(1),4-硝基苯基2,4-二硝基苯基(2)和双(2,4-二硝基苯基)(3)碳酸酯的反应在在25.0±0.1°C时,乙醇-水为44 wt%,离子强度为0.2M。在胺下,获得了过量的拟一级反应速率系数(k OBS)。的曲线ķ OBS针对在恒定pH游离胺的浓度是线性的,与斜坡ķ Ñ。苯胺分解1 – 3的布朗斯台德图(log k N vs.苯胺p K a)是线性的,斜率(β)值分别为0.52、0.61和0.63。这些斜率的值和其他考虑因素表明,这些反应是由协调机制决定的。对于这些反应,k N值遵循反应序列:3 > 2 > 1。即,反应性随着与非离去基团连接的硝基的数目增加而增加。与碳酸酯的逐步pyridinolysis这项工作的反应的比较1 - 3表明两性离子四面体中间体(T ±在吡啶分解反应中形成的α)通过等位苯胺基的吡啶部分的改变而不稳定。这归因于相对于等位吡啶,苯胺的T