Kinetics and mechanism of thermal gas-phase elimination of ?-substituted carboxylic acids: role of relative basicity of ?-substituents and acidity of incipient proton
作者:Nouria A. Al-Awadi、Kamini Kaul、Osman M. E. El-Dusouqui
2-Phenoxypropanoic acid together with five of its aryl derivatives, its phenylthio and its N-phenylamino analogues were pyrolyzed at 494–566 K. The reactions were homogeneous, polar and free from catalytic and radical pathways, and obeyed a first-order rate equation. The limits of the Arrhenius log A (s−1) and E (kJ mol−1) values obtained for these reactions averaged 11.98 ± 1.71 and 158.1 ± 17.4,
2-苯氧基丙酸及其五种芳基衍生物、苯硫基及其 N-苯氨基类似物在 494-566 K 下热解。反应均相、极性、无催化和自由基途径,并服从一级速率方程. 这些反应获得的 Arrhenius log A (s-1) 和 E (kJ mol-1) 值的平均值分别为 11.98 ± 1.71 和 158.1 ± 17.4。对热解物的分析表明消除产物是一氧化碳、乙醛和相应的苯酚、苯硫酚或苯胺化合物。还在 638-792 K 的温度范围内研究了 2-苯氧基和 2-(N-苯基氨基)-1-丙醇的热解。动力学结果和产物分析支持涉及五元环状极性的反应途径过渡状态。
Herbicidal 4-(benzotriazol-1-yl)phenoxy)alkanoic acids, esters and salts
申请人:Shell Oil Company
公开号:US04452626A1
公开(公告)日:1984-06-05
Certain 4-(benzotriazol-1-yl)phenoxy)alkanoic acids, esters and salts, useful as herbicides.
The present invention provides 2,4-pyrimidinediamine compounds that inhibit the IgE and/or IgG receptor signaling cascades that lead to the release of chemical mediators, intermediates and methods of synthesizing the compounds and methods of using the compounds in a variety of contexts, including in the treatment and prevention of diseases characterized by, caused by or associated with the release of chemical mediators via degranulation and other processes effected by activation of the IgE and/or IgG receptor signaling cascades.
The present invention provides 2,4-pyrimidinediamine compounds that inhibit the IgE and/or IgG receptor signaling cascades that lead to the release of chemical mediators, intermediates and methods of synthesizing the compounds and methods of using the compounds in a variety of contexts, including in the treatment and prevention of diseases characterized by, caused by or associated with the release of chemical mediators via degranulation and other processes effected by activation of the IgE and/or IgG receptor signaling cascades.
Merging excited-state copper catalysis and triplet nitro(hetero)arenes for direct synthesis of 2-aminophenol derivatives
作者:Jagrut A. Shah、Arghya Banerjee、Upasana Mukherjee、Ming-Yu Ngai
DOI:10.1016/j.chempr.2023.11.005
日期:2024.2
Nitro(hetero)arene derivatives are essential commodity chemicals used in various products, such as drugs, polymers, and agrochemicals. In this study, we leverage the excited-state reactivities of copper catalysts and nitro(hetero)arenes and the umpolung reactivity of acyl radicals to convert readily available nitro(hetero)arenes directly to valuable 2-aminophenol derivatives, which are important scaffolds
硝基(杂)芳烃衍生物是用于各种产品(例如药物、聚合物和农用化学品)的重要商品化学品。在这项研究中,我们利用铜催化剂和硝基(杂)芳烃的激发态反应性以及酰基自由基的反极性反应性,将容易获得的硝基(杂)芳烃直接转化为有价值的2-氨基苯酚衍生物,这是许多领域的重要支架。最畅销的药品。该反应适用于多种硝基(杂)芳烃、酰氯以及复杂分子的后期修饰,使其成为发现新功能分子的有用工具。机理研究,包括自由基捕获实验、Stern Volmer 猝灭研究、光开/关实验和 O 标记研究,表明反应机制涉及铜配合物的光激发、双自由基耦合和笼内接触离子对迁移。我们的研究结果提供了一种简化的方案,用于从硝基(杂)芳烃合成基本药效团,同时推进激发态和自由基化学的知识并刺激新的反应设计和开发。