Leibniz Institut für Katalyse e.V., Albert-Einstein-Straße 29a, 18059, Rostock, Germany.
ChemSusChem. 2023 May 5;16(9):e202202353. doi: 10.1002/cssc.202202353. Epub 2023 Mar 23.
Direct asymmetric reductive amination of bio-based levulinic acid (LA) to the enantioenriched 5-methylpyrrolidinone is achieved by using a readily available chiral Ru/bisphosphine catalyst with excellent enantioselectivity (up to 96 % ee) and high isolated yield (up to 89 %). Methyl levulinate (ML), a byproduct from the industrial production of 2,5-furandicarboxylic acid (FDCA), can be used instead of LA with similar reactivity and selectivity. Mass spectrometry and isotope labelling studies indicate that the chiral lactam is formed via imine-enamine tautomerization/cyclization followed by asymmetric hydrogenation of the cyclic enamide.
通过使用易得的手性 Ru/双膦催化剂，可将生物基戊二酸（LA）直接不对称还原胺化为对映体富集的 5-甲基吡咯烷酮，具有出色的对映选择性（高达 96%ee）和高分离产率（高达 89%）。甲酯（ML），是 2,5-呋喃二甲酸（FDCA）工业生产的副产物，其反应性和选择性与 LA 相似，可用作 LA 的替代品。质谱和同位素标记研究表明，手性内酰胺是通过亚胺-烯胺互变异构/环化形成的，随后对环状烯酰胺进行不对称氢化。
