Heterolytic dihydrogen activation by "antagonistic" Lewis pairs

一系列烯胺与Piers硼烷的硼氢化反应产生了新的分子内邻位N/B阻挫刘易斯对（FLP）。这些例子的特点是分子内氮硼相互作用较弱。对于手性实例，通过动态19 F NMR光谱测定活性FLP开环的活化势垒。制备了类似的P/B FLP，并测定了其弱P−B键断裂的活化势垒。这些新系统中的许多在温和条件下异相裂解氢。一些用作用于氢化富电子不饱和底物（烯胺、二烯胺、亚胺等）的无金属催化剂。我们还开发了一种用于FLP催化的贫电子烯烃和炔（大体积炔酮和烯酮）氢化的方案。这大大扩展了这些新的无金属主族元素二氢活化剂的应用潜力。

Hydroboration of a series of enamines with Piers’ borane gave new intramolecular vicinal N/B frustrated Lewis pairs (FLPs). These examples feature weak intramolecular nitrogenboron interactions. The activation barrier for ring opening to the active FLPs was determined for chiral examples by dynamic 19F NMR spectroscopy. Similar P/B FLPs were prepared and the activation barrier of the cleavage of their weak P−B bonds determined as well. Many of these new systems cleave dihydrogen heterolytically under mild conditions. Some serve as metal-free catalysts for the hydrogenation of electron-rich unsaturated substrates (enamines, dienamines, imines, etc.). We have also developed a protocol for FLP catalyzed hydrogenation of electron-poor olefins and alkynes (bulky ynones and enones). This has considerably extended the application potential of these new metal-free main-group element dihydrogen activators.