Cobalt-Catalyzed Hydrogenations via Olefin Cobaltate and Hydride Intermediates
Cobalt-Catalyzed Hydrogenations via Olefin Cobaltate and Hydride Intermediates
复制标题
DOI：
10.1021/acscatal.9b01584
复制
发表时间：
2019-07
期刊：
影响因子：
12.9
通讯作者：
Sebastian Sandl;Thomas M. Maier;N. P. van Leest;Susanne Kröncke;Uttam Chakraborty;S. Demeshko;K. Koszinowski;B. de Bruin;F. Meyer;M. Bodensteiner;C. Herrmann;R. Wolf;A. Jacobi von Wangelin
中科院分区：
文献类型：
--
作者：
Sebastian Sandl;Thomas M. Maier;N. P. van Leest;Susanne Kröncke;Uttam Chakraborty;S. Demeshko;K. Koszinowski;B. de Bruin;F. Meyer;M. Bodensteiner;C. Herrmann;R. Wolf;A. Jacobi von Wangelin
氧化还原非无辜配体是一种有前途的工具，以缓和电子转移过程中的贱金属催化剂。介绍了双亚胺苊钴配合物的加氢催化性能。通过使用稳定的催化剂前体[（DippBIAN）CoBr 2]和助催化剂LiEt 3BH，在温和条件（2-10巴，20-80 °C）下对位阻三取代烯烃、亚胺和喹啉进行清洁氢化。机理研究支持均相催化途径，涉及烯烃和钴酸盐作为活性催化剂物种。此外，观察到碱金属阳离子和刘易斯酸对反应的显著加速作用。双核钴酸根阴离子与桥接氢化物配体的分离和充分的特点。
Redox noninnocent ligands are a promising tool to moderate electron transfer processes within base-metal catalysts. This report introduces bis(imino)acenaphthene (BIAN) cobaltate complexes as hydrogenation catalysts. Sterically hindered trisubstituted alkenes, imines, and quinolines underwent clean hydrogenation under mild conditions (2–10 bar, 20–80 °C) by use of the stable catalyst precursor [(DippBIAN)CoBr2] and the cocatalyst LiEt3BH. Mechanistic studies support a homogeneous catalysis pathway involving alkene and hydrido cobaltates as active catalyst species. Furthermore, considerable reaction acceleration by alkali cations and Lewis acids was observed. The dinuclear hydridocobaltate anion with bridging hydride ligands was isolated and fully characterized.