Rhodium carbenoid-initiated Claisen rearrangement: scope and mechanistic observations.
Rhodium carbenoid-initiated Claisen rearrangement: scope and mechanistic observations.
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DOI：
10.1021/ol990697x
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发表时间：
1999-07
期刊：
影响因子：
5.2
通讯作者：
J. Wood;G. Moniz
中科院分区：
文献类型：
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作者：
J. Wood;G. Moniz
[公式：见正文]已经证明，在Rh（II）催化剂的存在下，α -重氮酮与烯丙醇反应生成中间烯醇，中间烯醇随后经过Claisen重排生成α -羟基酮。在此，我们报告了(1)对这一转化机制的研究，证实了Claisen重排既不是铑催化的，也不是酸催化的，而是中间烯醇固有的反应，以烯醇取代基（R3, R4, R5）控制的速率进行；(2)α -重氮酮与丙炔醇的反应，并对其范围和机制进行了初步调查。
[formula: see text] It has been shown that alpha-diazoketones react with allylic alcohols in the presence of Rh(II) catalysts to furnish intermediate enols which subsequently undergo Claisen rearrangement to alpha-hydroxyketones. Herein we report (1) studies into the mechanism of this transformation which establish that Claisen rearrangement is neither rhodium- nor acid-catalyzed but a reaction intrinsic to the intermediate enols that proceeds at a rate governed by enol substituents (R3, R4, R5) and (2) the reaction of alpha-diazoketones with propargylic alcohols and preliminary investigations into its scope and mechanism.