Ruthenium Complexes Containing Chiral N‐Donor Ligands as Catalysts in Acetophenone Hydrogen Transfer – New Amino Effect on Enantioselectivity
作者:Montserrat Gómez、Susanna Jansat、Guillermo Muller、Gabriel Aullón、Miguel Angel Maestro
DOI:10.1002/ejic.200500515
日期:2005.11
New p-cymene ruthenium species containing chiral amino alcohols (1–3), primary (4–7) and secondary (8, 9) amino-oxazolines, were tested as catalysts in the hydrogen transfer of acetophenone, using 2-propanol as the hydrogen source. A remarkable effect on the enantioselectivity, but also on the activity, was observed depending on the amino-type oxazoline, Ru/8 and Ru/9 being low active and nonselective
含有手性氨基醇 (1-3)、伯 (4-7) 和仲 (8, 9) 氨基恶唑啉的新对伞花烃钌物种被测试作为苯乙酮氢转移的催化剂,使用 2-丙醇作为催化剂氢源。根据氨基型恶唑啉、Ru/8 和 Ru/9 是低活性和非选择性催化体系,与其主要对应物 Ru/5 相比,观察到对映选择性和活性的显着影响。制备了含有氨基-恶唑啉 (10-12) 的配合物,并在溶液和固体状态下对其进行了充分表征。X 射线结构由 (SRu,RC)-10 确定。观察到的复合物 10 和 11 的非对映体比率由 1 H NMR 确定,并通过结构模型(半经验 PM3(tm) 水平)确认。氢转移过程中涉及的过渡态的 DFT 理论计算证明了它们相对种群的重要差异,这可以证明伯氨基-恶唑啉钌系统之间观察到的对映选择性差异是合理的。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany