Recent progress in Wacker oxidations: Moving toward molecular oxygen as the sole oxidant
Recent progress in Wacker oxidations: Moving toward molecular oxygen as the sole oxidant
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DOI：
10.1021/ic061858d
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发表时间：
2007-03-19
影响因子：
4.6
通讯作者：
Sigman, Matthew S.
中科院分区：
文献类型：
--
作者：
Cornell, Candace N.;Sigman, Matthew S.
瓦克氧化反应是用Pd（II）催化剂将末端烯烃转化为甲基酮的反应，已广泛应用于合成领域。标准的合成瓦克条件是在N，N-二甲基甲酰胺和H2O的混合溶剂体系中，在好氧气氛下使用PdCl2和化学计量CuCl催化。虽然很多人都关注于阐明核化的速率决定步骤和机制，但最近基于分离的Pd/Cu双金属物种和Cu对产物选择性的影响，Cu不参与这部分催化循环的假设受到了质疑。幸运的是，最近在消除Cu添加剂方面取得了进展，从而减轻了这些问题。这一领域的成功来自于研究其他直接o -2偶联Pd（II）氧化体系所获得的信息的应用，包括配体调制，这在Cu存在下是无法实现的。本文重点介绍了过氧化物介导和直接o -2偶联瓦克氧化的研究进展。
Wacker oxidations, the conversion of terminal olefins to methyl ketones with Pd(II) catalysts, have seen widespread use in synthetic applications. Standard synthetic Wacker conditions use catalytic PdCl2 with stoichiometric CuCl under an aerobic atmosphere in a mixed-solvent system of N,N-dimethylformamide and H2O. Though much attention has been directed toward elucidating the rate-determining step and the mechanism of nucleopalladation, the assumption that Cu does not participate in this portion of the catalytic cycle has recently been called into question based on an isolated Pd/Cu bimetallic species and the influence of Cu on product selectivity. Fortunately, recent advancements have been made toward the elimination of Cu additives, thereby alleviating these issues. Success in this area has come from the application of information gained in studying other direct-O-2-coupled Pd(II) oxidation systems, including ligand modulation, something which could not be achieved in the presence of Cu. The developments in peroxide-mediated and direct-O-2-coupled Wacker oxidations are highlighted herein.