Nitroalkenes in the Ni(II) Catalyzed Asymmetric<i>Michael</i>Addition. Convenient Route to the Key Intermediate of Brivaracetam
作者:Alexander N. Reznikov、Leonid E. Kapranov、Valentina V. Ivankina、Anastasiya E. Sibiryakova、Victor B. Rybakov、Yuri N. Klimochkin
DOI:10.1002/hlca.201800170
日期:2018.12
A series of Ni(II) complexes with novel chiral ligands derived from (1R,2R)‐1,2‐diphenylethane‐1,2‐diamine was synthesized. The catalytic activity of these complexes in the asymmetric Michael reaction is demonstrated. Asymmetric addition of diethyl malonate to ω‐nitrostyrene and 1‐nitropent‐1‐ene in the presence of these complexes leads to the enantiomerically enriched diethyl (S)‐2‐(2‐nitro‐1‐phenylethyl)malonate
合成了一系列具有新型手性配体的Ni(II)配合物,这些配体来自(1 R,2 R)-1,2-二苯乙烷-1,2-二胺。这些配合物在不对称迈克尔反应中的催化活性得到了证明。在这些络合物的存在下,将丙二酸二乙酯不对称添加到ω-硝基苯乙烯和1-硝基戊-1-烯中会导致对映异构体富集(S)-2-(2-硝基-1-苯乙基)丙二酸二乙酯(最高96%ee)和(R)2-(1-硝基戊基-2-基)丙二酸二乙酯(最高91%ee)。(4 R抗癫痫药布列西坦的关键中间体4-丙吡咯烷酮-2-酮是从相应的硝酸酯中获得的。