Multifunctional reactive intermediates: preparation, characterization, reactivity and catalysis

促进化学合成的主要因素之一是多功能反应中间体的制备、表征和控制。目前，标准化学技术通常采用单功能反应物质（有机金属、自由基、碳烯、阳离子、阴离子等），这严重阻碍了复杂结构的快速构建。因此，大多数全合成涉及大量步骤，因此既不节省原子/质量，也不节省能源。尽管在这一领域取得了巨大的进步，但更大范围的反应，特别是每一步化学步骤结构复杂性显著增加的试剂，是必要的。在本提案中，五个具有不同专业知识的小组合作制备和研究了多种多功能试剂和活性物质，这些试剂和活性物质可能是重要合成转化的中间产物。重点是主族元素试剂和活性中间体，从二金属和三金属碳氢化合物和硅烷，到官能化自由基和碳烯，到类似的硅基中间体，到类氧化物和类硝基，以及过渡金属官能化试剂。本研究结合了惰性基质中反应性中间体的合成、机理研究和分离及其光谱表征。它结合了实验和理论计算，这将为我们计划研究的许多新反应物质的性质提供额外的见解。总的来说，我们相信这项研究将丰富化学，提供许多新的多功能试剂和活性物质，为复杂分子的高效合成提供新的可能性。

One of the prime elements for advancing chemical synthesis is the preparation, characterization, and control of multi-functional reactive intermediates. Currently, standard chemical technology typically employs mono- functional reactive species (organometallics, radicals, carbenes, cations, anions, etc.) and this seriously hampers the rapid construction of complex structures. Hence, most total syntheses involve a large number of steps and consequently are neither atom / mass nor energy economic. Despite the tremendous progress in this area, a much larger panel of reactions and especially reagents achieving a significant increase in structural complexity per chemical step is necessary. In this proposal five groups with diverse expertise have teamed together to prepare and study a variety of multi- functional reagents and reactive species that are possible intermediates in important synthetic transformations. Emphasis is on main group element reagents and reactive intermediates spanning from di- and tri- metallo hydrocarbons and silanes, to functionalized radicals and carbenes, to the analogous silicon-based intermediates, to oxenoids and nitrenoids and to transition metal functionalized reagents. The proposed research combines synthesis, mechanistic studies and the isolation of reactive intermediates in inert matrix and their spectroscopic characterization. It combines experiment and theoretical calculations which will provide additional insights into the nature of the many new reactive species which we plan to study. Overall, we believe that this research will enrich chemistry with many new multifunctional reagents and reactive species providing new possibilities for efficient synthesis of complex molecules.