Danikiewicz Witold, Zimnicka Magdalena
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
Mass Spectrom Rev. 2016 Jan-Feb;35(1):123-46. doi: 10.1002/mas.21467. Epub 2015 Apr 6.
Reactions of aromatic and heteroaromatic compounds involving anions are of great importance in organic synthesis. Some of these reactions have been studied in the gas phase and are occasionally mentioned in reviews devoted to gas-phase negative ion chemistry, but no reviews exist that collect all existing information about these reactions. This work is intended to fill this gap. In the first part of this review, methods for generating arene anions in the gas phase and studying their physicochemical properties and fragmentation reactions are presented. The main topics in this part are as follows: processes in which gas-phase arene anions are formed, measurements and calculations of the proton affinities of arene anions, proton exchange reactions, and fragmentation processes of substituted arene anions, especially phenide ions. The second part is devoted to gas-phase reactions of arene anions. The most important of these are reactions with electrophiles such as carbonyl compounds and α,β-unsaturated carbonyl and related compounds (Michael acceptors). Other reactions including oxidation of arene anions and halogenophilic reactions are also presented. In the last part of the review, reactions of electrophilic arenes with nucleophiles are discussed. The best known of these is the aromatic nucleophilic substitution (SN Ar) reaction; however, other processes that lead to the substitution of a hydrogen atom in the aromatic ring are also very important. Aromatic substrates in these reactions are usually but not always nitroarenes bearing other substituents in the ring. The first step in these reactions is the formation of an anionic σ-adduct, which, depending on the substituents in the aromatic ring and the structure of the attacking nucleophile, is either an intermediate or a transition state in the reaction path. In the present review, we attempted to collect the results of both experimental and computational studies of the aforementioned reactions conducted since the very beginning of gas-phase negative ion chemistry.
涉及阴离子的芳香族和杂芳香族化合物的反应在有机合成中具有重要意义。其中一些反应已在气相中进行了研究，并且偶尔会在专门讨论气相负离子化学的综述中被提及，但目前尚无收集所有关于这些反应的现有信息的综述。这项工作旨在填补这一空白。在本综述的第一部分，介绍了在气相中生成芳烃阴离子并研究其物理化学性质和裂解反应的方法。这部分的主要主题如下：气相芳烃阴离子形成的过程、芳烃阴离子质子亲和力的测量和计算、质子交换反应以及取代芳烃阴离子，特别是苯负离子的裂解过程。第二部分专门讨论芳烃阴离子的气相反应。其中最重要的是与亲电试剂的反应，如羰基化合物、α,β-不饱和羰基及相关化合物（迈克尔受体）。还介绍了包括芳烃阴离子氧化和卤亲反应在内的其他反应。在综述的最后一部分，讨论了亲电芳烃与亲核试剂的反应。其中最著名的是芳香亲核取代（SN Ar）反应；然而，导致芳香环中氢原子被取代的其他过程也非常重要。这些反应中的芳香底物通常但不总是在环上带有其他取代基的硝基芳烃。这些反应的第一步是形成阴离子σ-加合物，根据芳香环中的取代基和进攻亲核试剂的结构，它在反应路径中要么是中间体，要么是过渡态。在本综述中，我们试图收集自气相负离子化学开始以来对上述反应进行的实验和计算研究的结果。
