A new synthetic concept was suggested in the chemistry of substituted methylidenemalonates that enables their utilization as 1,2-zwitterionic synthons. This strategy is to generate liquid ionic Ga complexes from methylidenemalonates and GaHal3 with a strict 3/4 composition and then use them in further synthesis. A number of complexes with different metal halides have been synthesized and studied in detail. The unique properties of gallium among all metals have been demonstrated and explained. On the basis of the discovered new class of gallium complexes of methylidenemalonates, a number of novel reactions with acetylenes have been elaborated, which are unknown in the conventional chemistry of methylidenemalonates. The main demonstrated process is a three-component addition to a triple bond involving halide anions, leading to the formation of polyfunctional vinyl halides with high E-selectivity. The mechanism has been studied experimentally in fine detail. Application of specially optimized 71Ga NMR spectroscopy makes it possible to take an in-depth look into the gallium chemistry in a new light. In particular, the key participation of GaHal4- anions in the occurring transformations has been established.

中文翻译：

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亚烷基和芳基亚甲基丙二酸酯的离子 Ga 络合物及其与乙炔的反应。深入了解发生的镓化学机制。

在取代亚甲基丙二酸酯的化学中提出了一种新的合成概念，可以将其用作 1,2-两性离子合成子。该策略是从具有严格 3/4 组成的亚甲基丙二酸酯和 GaHal3 生成液态离子 Ga 络合物，然后将它们用于进一步合成。已经合成并详细研究了许多具有不同金属卤化物的配合物。镓在所有金属中的独特性质已经得到证明和解释。在发现的一类新的亚甲基丙二酸镓配合物的基础上，已经阐述了许多与乙炔的新反应，这些反应在亚甲基丙二酸的常规化学中是未知的。主要展示的过程是对涉及卤化物阴离子的三键进行三组分加成，导致形成具有高 E 选择性的多官能卤乙烯。已经通过实验详细地研究了该机制。特别优化的 71Ga 核磁共振光谱的应用使得以新的视角深入研究镓化学成为可能。特别是，GaHal4-阴离子在发生的转变中的关键参与已经确立。