New frustrated Lewis pair catalyzed addition reactions

溶液中路易斯酸性中心和刘易斯碱性中心共存，使得单个反应活性不被熄灭，这被引入为受挫Lewis对(FLP)现象。这一特征导致了无金属的氢裂解，后来又激活了其他小分子，如二氧化碳、一氧化碳或硝基氧化物。加氢反应具有很高的化学意义，是目前FLP化学中最吸引人的反应。一方面，FLP化学最大的收获是它与过渡金属加氢反应的互补性。许多底物，例如含有卤化物或重氮的分子与过渡金属催化的氢化反应是不相容的。因此，FLP化学可以成为过程化学和研究化学中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)来将这一概念提高到更一般的水平。目前的研究计划针对FLP化学的两个中心问题：(1)FLP催化的加氢将发展为一种强有力的工具，用于过渡金属不相容的底物的加氢，例如含卤化物的化合物、偶氮衍生物或重氮盐。目前，这些化合物类别通过与硼氢化物、联氨或亚硫酸钠的化学计量反应进行还原，导致大量废物和安全隐患。在这里，FLP催化加氢是规避这些问题的关键技术。(2)FLP化学将扩展到X-Y片段的转移反应，例如C-H，N-H和C-Si键，跨越多个键。类似于氢-氢转移到无金属烯烃的氢胺化反应，不饱和化合物的氢三氟甲基化和硅基氰化反应将为FLP催化的反应开辟新的方面。这两种方法的共同重叠之处是同时调制了硼烷衍生的Lewis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节。这些发展不仅将扩大FLP的反应性，还将允许更高的官能团容忍度。这也将大大提高硼烷对空气和水分的稳定性，为有机合成提供强有力的方法。

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.