Aggregation and Reactivity of Organocuprates

有机铜酸盐是非常有价值的有机金属试剂，其经典变体通过铜（I）前体与有机锂或镁化合物的金属交换形成。在第一个供资期间，对这些试剂在溶液中的形态及其反应性进行了相当详细的检查。在所要求的第二个供资期内，应探索通过与有机锌、硼和硅化合物的金属交换制备有机铜酸盐、-银酸盐和-金酸盐。这些试剂具有更高的官能团耐受性的巨大优势，但同时可以预期它们的有机基团不太容易转移到铸币金属中心。本提案旨在确定控制钴金属的金属转移的因素，以便找到新的和改进的方法来获取有机铜酸盐及其较重的同系物。为此，将采取双管齐下的战略。首先，一个严格的还原论的方法将适用于探测的单分子反应性的定义明确的双离子在气相中。串联质谱法将确定这些离子进行transmethalide的趋势，并显示反应效率如何取决于金属的性质，有机基团的电子和空间性质，以及金属结合的卤化物和其他阴离子的存在。第二，溶液中的反应体系的组成将通过电喷雾电离质谱，多核NMR光谱和纳米量热法的组合来阐明。气相和液相实验都将通过量子化学计算来补充，以获得有关中间体和过渡态的能量学和结构的信息。因此，拟议的研究，不仅提供了基本的洞察机制的原型transmethalo反应，但也使合理的发展新的钴金属，其合成潜力将被测试选定的例子。

Organocuprates are exceedingly valuable organometallic reagents, the classical variants of which are formed by the transmetallation of copper(I) precursors with organolithium or magnesium compounds. In the first funding period, the speciation of these reagents in solution and their reactivity were examined in considerable detail. In the requested second funding period, the preparation of organocuprates, -argentates, and -aurates by the transmetallation with organozinc, -boron, and -silicon compounds shall be explored. These reagents have the great advantage of a higher functional-group tolerance, but at the same time can be expected to transfer their organyl groups less readily to the coinage-metal center. The present proposal aims at identifying the factors that control the transmetallation of the coinage metals in order to find new and improved ways to access organocuprates and their heavier homologues. To this end, a twofold strategy will be pursued. First, a rigorously reductionist approach will be applied by probing the unimolecular reactivity of well-defined bimetallic ions in the gas phase. Tandem-mass spectrometry will determine the tendency of these ions to undergo transmetallation and show how the reaction efficiency depends on the nature of the metals, the electronic and steric properties of the organyl group, and the presence of metal-bound halides and other anions. Second, the composition of the reaction systems in solution will be elucidated by a combination of electrospray-ionization mass spectrometry, multinuclear NMR spectroscopy, and nanocalorimetry. Both the gas- and the solution-phase experiments will be complemented by quantum chemical calculations to obtain information on the energetics and structures of the involved intermediates and transition states. The proposed studies, thus, shall not only afford fundamental insight into the mechanism of prototypical transmetallation reactions, but also enable the rational development of new coinage metallates, whose synthetic potential will be tested for selected examples.