Reactivities of electron-deficient arenes

该项目将利用有关有机分子的亲电和亲核反应的定量信息，开发前所未有的通过缺电子芳烃(EDAS)的脱芳烃反应进行有机合成的方法。为了在分子水平上揭示EDA/亲核反应的各个步骤，将应用分子化学和量子化学分子建模的策略，并将其与动力学和热力学研究相结合。法国和德国研究人员在这项联合提案中的联合专业知识将产生新的机械见解和创新的合成路线，包括高压和流动化学，用于以可预测和可控制的方式组装新的复杂的三维杂环分子结构。有机合成中使用的大多数反应可以看作是亲电性和亲核性的组合，应用Mayr-Patz方程(MPE)lgk(20°C)=SN(N+E)提供了一个分类来预测给定亲电-亲核偶的反应速率。在这个项目中，我们将校准EDAS的亲电性(E)，它能够与富电子实体进行加成和(x+2)环加成。研究将包括迈克尔加成，其中形成一个新的西格马键，以及协调过程。所研究的亲核试剂将覆盖稳定的分子，如二烯胺或甲亚胺，并将扩展到由激光闪光诱导光烯醇化产生的短暂的“光烯醇”。MPE的应用定义了EDA亲核反应的速率下限，该反应涉及在速率确定步骤中形成新的单键。过渡态受益于两个以上反应中心之间相互作用的环加成反应进行得更快。这种协同的环加成反应将通过高水平的密度泛函方法在高压下进一步研究，以开发其合成潜力。

This project will use quantitative information about the electrophilic and nucleophilic reactivity of organic molecules to develop unprecedented approaches to organic syntheses through dearomative reactions of electron-deficient arenes (EDAs). To unravel the individual steps of EDA/nucleophile reactions at the molecular level, strategies in molecular chemistry and quantum-chemical molecular modeling will be applied and beneficially synergized with kinetic and thermodynamic studies. The combined expertise of the French and German researchers in this joint proposal will generate new mechanistic insights and innovative synthetic routes, including high pressure and flow chemistry, for the assembly of new complex three-dimensional heterocyclic molecular architectures in a predictable and controlled manner. The majority of reactions used in organic synthesis can be considered as combinations of electrophiles with nucleophiles and the application of the Mayr-Patz equation (MPE), lg k(20 °C) = sN(N + E), provides a classification to predict the reaction rates for a given electrophile-nucleophile couple. In this project, we will calibrate the electrophilicity (E) of EDAs capable of performing additions and (x+2) cycloadditions with electron-rich entities. Studies will include Michael additions, in which a single new sigma bond is formed, as well as concerted processes. The nucleophiles studied will cover stable molecules, such as dienamines or azomethine imines, and will extend to short-lived "photo-enols" generated by laser-flash induced photoenolizations. The application of the MPE defines the lower limit of rates for EDA-nucleophilic reactions involving the formation of a new single bond in the rate-determining step. Cycloadditions whose transition states benefit from interactions between more than two reaction centers proceed more rapidly. Such concerted cycloadditions will be further investigated by high-level DFT methods and under high-pressure to exploit their synthetic potential.