State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, China.
Chemistry. 2010 Feb 22;16(8):2496-502. doi: 10.1002/chem.200902321.
We report here the intramolecular reactions between alpha,beta-epoxy ketones and alkynes cocatalyzed by gold(I) and Yb(OTf)(3). This new catalytic system based on a combination of gold(I) and Yb(OTf)(3) allows facile transformation of epoxy alkynes to give novel indene derivatives in moderate to good yields under mild conditions. Moreover, we describe here the first observation of a transfer of a carbonyl group in a five-membered carbocycle during gold-catalyzed reactions. This proposed mechanism is corroborated by isotope-labeling experiments (D and (13)C). Furthermore, the probable role of each catalyst in this interesting domino reaction has been examined by (31)P NMR experiments. The utilization of gold catalysts combined with rare-earth metal salts offers a new concept for the design of catalyst combinations for domino or cascade reactions.
我们在此报告了在金（I）和 Yb（OTf）（3）共催化下，α，β-环氧酮与炔烃的分子内反应。这种基于金（I）和 Yb（OTf）（3）结合的新型催化体系允许在温和条件下轻松地将环氧炔烃转化为新型茚衍生物，产率中等至良好。此外，我们在这里首次观察到在金催化反应中，五员碳环中的羰基基团发生转移。通过同位素标记实验（D 和（13）C）证实了该反应机理。此外，通过（31）P NMR 实验研究了每种催化剂在这种有趣的串联反应中的可能作用。金催化剂与稀土金属盐的结合为设计用于串联或级联反应的催化剂组合提供了新概念。
