Sandl Sebastian, Schwarzhuber Felix, Pöllath Simon, Zweck Josef, Jacobi von Wangelin Axel
Institute of Organic Chemistry, University of Regensburg, Germany.
Institute of Experimental and Applied Physics, University of Regensburg, Germany.
Chemistry. 2018 Mar 7;24(14):3403-3407. doi: 10.1002/chem.201705366. Epub 2018 Feb 8.
The development of cobalt catalysts that combine easy accessibility and high selectivity constitutes a promising approach to the replacement of noble-metal catalysts in hydrogenation reactions. This report introduces a user-friendly protocol that avoids complex ligands, hazardous reductants, special reaction conditions, and the formation of highly unstable pre-catalysts. Reduction of CoBr with LiEt BH in the presence of alkenes led to the formation of hydrogenation catalysts that effected clean conversions of alkenes, carbonyls, imines, and heteroarenes at mild conditions (3 mol % cat., 2-10 bar H , 20-80 °C). Poisoning studies and nanoparticle characterization by TEM, EDX, and DLS supported the notion of a heterotopic catalysis mechanism.
开发兼具易于获取和高选择性的钴催化剂是在氢化反应中替代贵金属催化剂的一种有前景的方法。本报告介绍了一种用户友好的方法，该方法避免了使用复杂配体、危险还原剂、特殊反应条件以及形成高度不稳定的预催化剂。在烯烃存在下用LiEtBH还原CoBr会生成氢化催化剂，该催化剂能在温和条件下（3 mol%催化剂，2 - 10 bar H，20 - 80°C）实现烯烃、羰基化合物、亚胺和杂芳烃的完全转化。中毒研究以及通过TEM、EDX和DLS对纳米颗粒进行的表征支持了异位催化机理的观点。
