Muñiz Kilian, Iesato Atsushi, Nieger Martin
Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany.
Chemistry. 2003 Nov 21;9(22):5581-96. doi: 10.1002/chem.200305011.
The diamination of certain olefins bearing electron-withdrawing substituents proceeds with well-defined bisimido and trisimido complexes of osmium. The products are obtained as osmaimidazolidines which are of unprecedented stability with regards to olefin functionalisation. Osmium complexes from related dihydroxylation or aminohydroxylation are significantly less stable and thereby promote catalytic reactions. This difference in reaction profile has been investigated and chiral osmium heterocycles obtained from olefin difunctionalisation were characterised by X-ray analysis for the first time. Kinetic studies on the reaction profile have also been carried out. An asymmetric version of this reaction is based on chiral non-racemic auxiliaries and leads to diastereomerically enriched osmaimidazolidines with up to 90 % de. This sequence represents the first asymmetric diamination of olefins. Attempts on the use of chiral ligands for direct asymmetric diamination as well as the consequences of osmaimidazolidine properties for a catalytic reaction are discussed.
某些带有吸电子取代基的烯烃的双胺化反应是通过定义明确的锇双亚胺和三亚胺配合物进行的。产物以锇咪唑烷的形式获得，就烯烃官能化而言，其具有前所未有的稳定性。来自相关二羟基化或氨基羟基化的锇配合物稳定性明显较低，因此能促进催化反应。已对这种反应特征的差异进行了研究，首次通过X射线分析对烯烃双官能化得到的手性锇杂环进行了表征。还对反应特征进行了动力学研究。该反应的不对称形式基于手性非外消旋助剂，可得到非对映体过量高达90%的非对映体富集锇咪唑烷。该序列代表了烯烃的首次不对称双胺化反应。讨论了使用手性配体进行直接不对称双胺化的尝试以及锇咪唑烷性质对催化反应的影响。
