Gold(I)-Catalyzed Rearrangement of 3-Silyloxy-1,5-enynes: An Efficient Synthesis of Benzo[b]thiophenes, Dibenzothiophenes, Dibenzofurans, and Indole Derivatives
Gold(I)-Catalyzed Rearrangement of 3-Silyloxy-1,5-enynes: An Efficient Synthesis of Benzo[b]thiophenes, Dibenzothiophenes, Dibenzofurans, and Indole Derivatives
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DOI：
10.1002/chem.201200314
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发表时间：
2012-05-01
影响因子：
4.3
通讯作者：
Rominger, Frank
中科院分区：
文献类型：
--
作者：
Hashmi, A. Stephen K.;Yang, Weibo;Rominger, Frank
用IPr配体（IPr= 1，3-双-（2，6-二异丙基苯基）咪唑-2-亚基）在金（I）上进行的2-取代噻吩、苯并噻吩、吡咯、苯并呋喃和吲哚的苯甲酰化反应中获得了优异的产率。1-炔基丁-3-炔基侧链，结合在anellation，是很容易获得的通过添加炔丙基金属试剂的甲酰基和硅烷化的醇。这方便地允许在温和条件下在甲酰基的位置处进行酯化。所有反应都涉及在anellation步骤中侧链的2，3-移位，因此，提供了一种容易获得特定取代模式的方法。只有在具有高度亲核性3-位的2-取代吲哚的情况下，才观察到没有位移的直接氢化芳基化。另一方面，3-取代吲哚得到与2-取代吲哚相同的产物。然后，吲哚环系统中的3，2-位移必须涉及。
With the IPr ligand (IPr=1,3-bis-(2,6-diisopropylphenyl)imidazol-2-ylidene) on gold(I) excellent yields in the benzanellation of 2-substituted thiophenes, benzothiophenes, pyrroles, benzofurans, and indoles were achieved. The 1-siloxybut-3-ynyl side chains, incorporated in the anellation, are easily accessible by the addition of a propargyl metal reagent to a formyl group and silylation of the alcohol. This conveniently allows an anellation at the position of the formyl group under mild conditions. All reactions involve a 2,3-shift of the side chain in the anellation step and thus, provide an easy access to specific substitution patterns. Only in the case of 2-substituted indoles with their highly nucleophilic 3-position a direct hydroarylation without shift is observed. On the other hand, 3-substituted indoles give the same products as 2-substituted indoles. Then, a 3,2-shift in the indole ring system has to be involved.