New frustrated Lewis pair catalyzed addition reactions

溶液中刘易斯酸和刘易斯碱位点的共存，使得单个反应活性不淬灭，这被称为受挫刘易斯对（FLP）现象。这一特征导致了无金属氢的解理，后来导致了其他小分子的活化，如二氧化碳、一氧化碳或硝基氧化物。氢化反应是迄今为止flp化学中最引人注目的反应，具有重要的化学意义。一方面，flp化学的最大收获是它与过渡金属基氢化的互补性。许多底物，如含卤化物或重氮的分子，与过渡金属催化的氢化反应不相容。因此，flp化学可以在工艺化学和研究化学中成为一种强有力的补充方法。另一方面，必须找到新的flp介导的键激活（C-H或C-Si）来将这一概念提升到更普遍的水平。本研究计划针对flp化学的两个核心问题：(1)flp催化的加氢将成为过渡金属不相容底物（如含卤化物化合物、偶氮衍生物或重氮盐）加氢的有力工具。这些化合物类别目前通过与硼氢化物、肼或亚硫酸钠的化学计量反应来减少，从而产生大量废料和安全危害。在这里，flp催化氢化是规避这些问题的关键技术。(2) flp化学将扩展到X-Y片段跨多个键的转移反应，如C-H、N-H和C-Si键。与H-H转移到烯烃的无金属氢胺化类似，不饱和化合物的氢三氟甲基化和硅基氰化将开辟flp催化反应的新方面。这两种方法的共同重叠之处是同时调制硼烷衍生的刘易斯酸的电子和空间性质。因此，路易斯酸的反应性可以根据应用进行调整。这些发展不仅将扩大FLP的反应性，而且将允许更高的官能团耐受性。这也将导致硼烷对空气和水分的稳定性显著提高，为有机合成提供有力的方法。

The coexistence of a Lewis-acidic and a Lewis-basic site in solution, which leaves the individual reactivity unquenched, was introduced as the phenomenon of a frustrated Lewis pair (FLP). This feature led to the metal-free hydrogen cleavage and later to the activation of other small molecules, e. g. carbon dioxide, carbon monoxide or nitro oxides. The hydrogenation is the most appealing reaction in FLP-chemistry to date due to the high significance in chemistry. On the one hand, the biggest gain of FLP-chemistry is its complementarity to transition metal-based hydrogenations. A number of substrates e. g. halide- or diazonium-containing molecules are incompatible with transition metal-catalyzed hydrogenations. For those, FLP-chemistry can advance to a powerful and complementary method in process and research chemistry. On the other hand, novel FLP-mediated bond-activations (C-H or C-Si) must be found to advance this concept to a more general level. The presented research program targets both central issues of FLP-chemistry: (1) The FLP-catalyzed hydrogenation will be advanced to a powerful tool for the hydrogenation of transition-metal incompatible substrates, e. g. halide-bearing compounds, azo-derivatives or diazonium salts. These compound classes are currently reduced by stoichiometric reaction with borohydrides, hydrazine or sodium sulfite, giving rise to large amounts of waste material and safety hazards. Here, the FLP-catalyzed hydrogenation is the key technology to circumvent these issues. (2) The FLP-chemistry will be extended to transfer reactions of X-Y fragments, e. g. C-H, N-H and C-Si bonds, across multiple bonds. In analogy to the H-H transfer to olefins metal-free hydroaminations, hydrotrifluoromethylations and silylcyanations of unsaturated compounds will open new aspects of FLP-catalyzed reactions. The common overlap of both approaches is the simultaneous modulation of electronic and steric properties of the borane-derived Lewis-acids. Thereby the Lewis-acid's reactivity can be tuned to the application. These developments will not only broaden the FLP's reactivity but will also permit higher functional group tolerance. This will also lead to significant stability improvements of the borane towards air and moisture affording powerful methods for organic synthesis.