Multifunctional reactive intermediates: preparation, characterization, reactivity and catalysis

多官能团活性中间体的制备、表征和控制是推动化学合成的主要内容之一。目前，标准的化学技术通常使用单功能活性物种(有机金属、自由基、卡宾、阳离子、阴离子等)。这严重阻碍了复杂结构的快速建设。因此，大多数全合成涉及大量的步骤，因此既不是原子/质量，也不是能源经济。尽管在这一领域取得了巨大的进步，但需要更多的反应，特别是试剂，以实现每个化学步骤结构复杂性的显著增加。在这项提案中，具有不同专业知识的五个小组联手准备和研究各种多功能试剂和活性物种，这些试剂和活性物种可能是重要合成转化中的中间体。重点介绍了主要的族元素试剂和反应中间体，从二、三金属碳氢化合物和硅烷，到官能化的自由基和卡宾，到类似的硅基中间体，到恶烯和硝烯类化合物，以及过渡金属功能化试剂。建议的研究结合了合成、机理研究、惰性基质中活性中间体的分离及其光谱表征。它结合了实验和理论计算，这将为我们计划研究的许多新的活性物种的性质提供更多的见解。总体而言，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种，为高效合成复杂分子提供新的可能性。

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.