Lyons Thomas W, Sanford Melanie S
University of Michigan, Department of Chemistry, 930 N. University Ave., Ann Arbor, MI 48109, USA.
Tetrahedron. 2009 Apr 18;65(16):3211-3221. doi: 10.1016/j.tet.2008.10.107.
This report describes detailed studies of the scope and mechanism of a new Pd-catalyzed oxidation reaction for the stereospecific conversion of enynes into cyclopropyl ketones. Unlike related Pd(II/0), Au, and Pt-catalyzed cyclopropane-forming reactions, these transformations proceed with net inversion of geometry with respect to the starting alkene. This result, along with other mechanistic data, is consistent with a Pd(II/IV) mechanism in which the key cyclopropane-forming step involves nucleophilic attack of a tethered olefin onto the Pd(IV)-C bond.
本报告描述了一种新型钯催化氧化反应的范围和机理的详细研究，该反应可将烯炔立体定向转化为环丙基酮。与相关的钯（II/0）、金和铂催化的环丙烷形成反应不同，这些转化过程相对于起始烯烃发生了净几何构型反转。这一结果与其他机理数据一致，支持了一种钯（II/IV）机理，其中关键的环丙烷形成步骤涉及连接的烯烃对钯（IV）-碳键的亲核进攻。
