Gold-Catalyzed Annulations of 2-Alkynyl Benzaldehydes with Vinyl Ethers: Synthesis of Dihydronaphthalene, Isochromene, and Bicyclo[2.2.2]octane Derivatives
作者:Deepika Malhotra、Le-Ping Liu、Mark S. Mashuta、G. B. Hammond
DOI:10.1002/chem.201203841
日期:2013.3.18
appropriate control of the reaction conditions, various new gold‐catalyzed cyclizations of 2‐alkynyl benzaldehyde with acyclic or cyclic vinyl ethers have been developed. Acetal‐tethered dihydronaphthalene and isochromenes were obtained from the reactions of 2‐alkynyl benzaldehydes with acyclic vinyl ethers under mild conditions. And, more interestingly, the gold‐catalyzed reactions of 2‐alkynyl benzaldehyde
用金催化剂的合适的选择以及反应条件适当的控制,与无环或环状乙烯基醚2 -炔基苯甲醛的各种新的金催化的环化得到了发展。在温和的条件下,由乙炔基苯甲醛与无环乙烯基醚反应制得乙缩醛系二氢萘和异色酮。而且,更有趣的是,2-炔基苯甲醛与环状乙烯基醚的金催化反应提供了涉及两个分子的环状乙烯基醚的双环[2.2.2]辛烷衍生物。这些产品包含在许多生物活性分子和天然产品中发现的有趣的亚结构。此外,金催化的2-苯基乙炔基苯甲醛1 a的均二聚当在不存在乙烯基醚的情况下进行反应时,观察到α-烯烃,得到一组可分离的非对映体产物。讨论了这些转换的合理机制。含金的苯并吡啶被认为是许多这些新的转化发生的关键中间体。