Inorganic Chemistry II-Catalyst Design, University of Bayreuth, 95440, Bayreuth, Germany.
Angew Chem Int Ed Engl. 2020 Jul 13;59(29):11789-11793. doi: 10.1002/anie.202001704. Epub 2020 May 18.
The alkylation of amines by alcohols is a broadly applicable, sustainable, and selective method for the synthesis of alkyl amines, which are important bulk and fine chemicals, pharmaceuticals, and agrochemicals. We show that Cr complexes can catalyze this C-N bond formation reaction. We synthesized and isolated 35 examples of alkylated amines, including 13 previously undisclosed products, and the use of amino alcohols as alkylating agents was demonstrated. The catalyst tolerates numerous functional groups, including hydrogenation-sensitive examples. Compared to many other alcohol-based amine alkylation methods, where a stoichiometric amount of base is required, our Cr-based catalyst system gives yields higher than 90 % for various alkyl amines with a catalytic amount of base. Our study indicates that Cr complexes can catalyze borrowing hydrogen or hydrogen autotransfer reactions and could thus be an alternative to Fe, Co, and Mn, or noble metals in (de)hydrogenation catalysis.
醇对胺的烷基化是一种广泛适用、可持续且具有选择性的合成烷基胺的方法，而烷基胺是重要的大宗和精细化学品、药物和农用化学品。我们证明了 Cr 配合物可以催化这种 C-N 键形成反应。我们合成并分离了 35 个烷基化胺的实例，包括 13 个以前未公开的产物，并证明了使用氨基醇作为烷基化剂。该催化剂可以容忍许多官能团，包括对氢化敏感的例子。与许多其他基于醇的胺烷基化方法相比，这些方法需要化学计量的碱，我们基于 Cr 的催化剂体系在催化量的碱存在下，对各种烷基胺的产率高于 90%。我们的研究表明，Cr 配合物可以催化借氢或氢自动转移反应，因此可以替代（脱氢）催化中的 Fe、Co 和 Mn 或贵金属。
