157977-91-8Relevant academic research and scientific papers
Iridium-Catalyzed Asymmetric Hydrogenation of Unsaturated Piperazin-2-ones
Wang, Yanzhao,Liu, Yuanyuan,Li, Kun,Yang, Guoqiang,Zhang, Wanbin
, p. 1933 - 1941 (2017/06/09)
Two different iridium catalyst systems, generated from the ruthenocene-based phosphine-oxazoline ligand tBu-mono-RuPHOX or the diphosphine ligand BINAP, were developed for the asymmetric hydrogenation of 5,6-dihydropyrazin-2(1H)-ones, affording chiral piperazin-2-ones in good yields and with moderate to good ees. Different catalytic behaviors for the hydrogenation of these types of substrate were observed with these two catalyst systems. Our tBu-mono-RuPHOX ligand, which bears a ruthenocene scaffold with planar chirality, was found to be the best ligand for the [Ir(L)(COD)]BArF catalyst system, affording the desired products with up to 94% ee. (Figure presented.).
