Carboxylic acids are valuable organic substrates as they are widely available, easy to handle, and exhibit structural and functional variety. While they are used in many standard synthetic protocols, over the past two decades numerous studies have explored new modes of metal-mediated reactivity of carboxylic acids and their derivatives. Mass spectrometry-based studies can provide fundamental mechanistic insights into these new modes of reactivity. Here gas-phase models for the following catalytic transformations of carboxylic acids and their derivatives are reviewed: protodecarboxylation; dehydration; decarbonylation; reaction as coordinated bases in C–H bond activation; remote functionalization and decarboxylative C–C bond coupling. In each case the catalytic problem is defined, insights from gas-phase studies are highlighted, comparisons with condensed-phase systems are made and perspectives are reached. Finally, the potential role for mechanistic studies that integrate both gas- and condensed-phase studies is highlighted by recent studies on the discovery of new catalysts for the selective decomposition of formic acid and the invention of the new extrusion-insertion class of reactions for the synthesis of amides, thioamides, and amidines. © 2020 John Wiley & Sons Ltd. Mass Spec Rev

中文翻译：

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有机金属气相离子化学和催化：深入了解使用金属催化剂促进羧酸及其衍生物反应的选择性

羧酸是有价值的有机底物，因为它们广泛可用、易于处理，并且具有结构和功能的多样性。虽然它们被用于许多标准合成方案，但在过去的二十年中，许多研究探索了羧酸及其衍生物的金属介导反应性的新模式。基于质谱的研究可以为这些新的反应模式提供基本的机制见解。这里回顾了羧酸及其衍生物的以下催化转化的气相模型：原脱羧；脱水; 脱羰; 在 C-H 键活化中作为配位碱基的反应；远程功能化和脱羧C-C键偶联。在每种情况下，都定义了催化问题，突出了气相研究的见解，与凝聚相系统进行了比较，并达成了观点。最后，最近关于发现用于甲酸选择性分解的新催化剂和发明用于酰胺、硫代酰胺和脒的合成。© 2020 John Wiley & Sons Ltd. 质谱修订版 和脒。© 2020 John Wiley & Sons Ltd. 质谱修订版 和脒。© 2020 John Wiley & Sons Ltd. 质谱修订版