Catalyzed tandem reaction of 3-silyloxy-1,5-enynes consisting of cyclization and pinacol rearrangement
Catalyzed tandem reaction of 3-silyloxy-1,5-enynes consisting of cyclization and pinacol rearrangement
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DOI：
10.1002/anie.200604544
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发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Menz, Helge
中科院分区：
文献类型：
--
作者：
Kirsch, Stefan F.;Binder, Joerg T.;Menz, Helge
天然产物和日益复杂的药物制剂的有效构建需要不断开发用于其立体控制合成的新方法。在这种情况下，由频哪醇重排终止的阳离子环化反应已被证明具有特殊的价值。[1-3]例如，Overman及其同事使用由Prins环化和频哪醇反应组成的串联反应来合成氧杂环和碳环天然产物，例如（N）-柠檬酸病毒[4]和（+）-shahamin K。[5]虽然已经对各种引发基团进行了相当详细的研究[6]，但在这种情况下π系统的活化还没有得到很好的理解。[7]在此，我们报道了第一个由金催化的炔活化引发的串联环化-频哪醇反应。作为我们在该领域正在进行的研究的一部分，[8]我们鉴定了3-甲硅氧基-1，5-烯炔作为一类潜在有用的底物（方案1）。设想软阳离子与炔基官能团的配位可能引发6-内二碳环化。[9-11]在我们预测的序列中，阳离子中间体[12]预计将经历不可逆的频哪醇
The efficient construction of natural products and increasingly complex pharmaceutical agents requires the ongoing development of new methods for their stereocontrolled synthesis. Within this context, cationic cyclization reactions terminated by a pinacol rearrangement have been shown to be of exceptional value.[1–3] For example, Overman and coworkers used a tandem reaction consisting of a Prins cyclization and a pinacol reaction for the synthesis of oxacyclic and carbocyclic natural products such as (À)-citreoviral [4] and (+)-shahamin K.[5] While various initiating groups have already been investigated in considerable detail,[6] the activation of π systems in this context is not well understood.[7] Herein we report the first tandem cyclization–pinacol reaction that is initiated by gold (I)-catalyzed alkyne activation.As part of our ongoing studies in this field,[8] we identified 3-silyloxy-1, 5-enynes as a potentially useful class of substrates (Scheme 1). It was envisaged that coordination of a soft cation to the alkynyl functionality might initiate a 6-endo-dig carbocyclization.[9–11] In our projected sequence the cationic intermediate [12] is expected to undergo an irreversible pinacol