Synthesis of Chiral Catalyst Modifiers by Hydrosilylation of Cinchonidine and Their Application in the Hydrogenation of 1-Phenylpropane-1,2-dione and Ethyl Pyruvate on a Supported Pt/Al2O3 Catalyst
作者:Igor Busygin、Esa Toukoniitty、Reijo Sillanpää、Dmitry Yu. Murzin、Reko Leino
DOI:10.1002/ejoc.200500161
日期:2005.7
Four new chiral modifiers were synthesized in order to investigate the effect of distal modifier substitution in the hydrogenation of ethyl pyruvate and 1-phenylpropane-1,2-dione on a supported Pt/Al2O3 catalyst. The chiral modifiers were prepared in good to moderate overall yields by Pt-catalyzed hydrosilylation of 9-O-TMS-protected cinchonidine with triethylsilane, triphenylsilane, bis(dimethylsilyl)ethane
合成了四种新的手性改性剂,以研究远端改性剂取代在丙酮酸乙酯和 1-苯基丙烷-1,2-二酮在负载型 Pt/Al2O3 催化剂上加氢过程中的影响。通过 9-O-TMS 保护的辛可尼丁与三乙基硅烷、三苯基硅烷、双(二甲基甲硅烷基)乙烷和(+)-(R)-甲基(1-萘基)的 Pt 催化氢化硅烷化,以良好至中等的总产率制备了手性改性剂苯基硅烷,然后裂解甲硅烷基醚保护基团。报告了使用辛可尼丁作为参考改性剂的对映选择性氢化中合成改性剂的比较,以及它们合成和表征的详细信息。已确定 11-(三苯基甲硅烷基)-取代的辛可尼丁类似物的 X 射线晶体结构表明,该化合物以早先观察到的 (-)-辛可尼丁的开放 (3) 样构象结晶。在丙酮酸乙酯的氢化中,新的改性剂引起了显着的对映体过量(ee = 62-73 %),然而,这比用辛可尼丁作为手性催化剂改性剂获得的 ee 略低(ee = 84 %)。在没有手性改性剂的情况下,