这篇完整的报告介绍了两种不同羰基物质的氧化分子间偶联的背景、发现和广泛的见解。该过程的优化最终形成了使用可溶性铜 (II) 或铁 (III) 盐作为氧化剂将酰胺、酰亚胺、酮和羟吲哚结合的可靠且可扩展的方案。广泛的机理研究表明,在铜 (II) 的情况下是金属螯合的单电子转移过程,而基于铁 (III) 的偶联似乎是通过非模板化的异二聚化进行的。这项工作提供了迄今为止对氧化烯醇偶联机制最深入的发现。氧化烯醇杂偶联的范围很广(40 个例子),并且已被证明即使在大规模(克级或更大)上也是有效的。最后,
It′s the iodine: The intra‐ and intermolecular title reaction is catalyzed by an in situgenerated ammonium (hypo)iodite species. Either H2O2 or tert‐butyl hydroperoxide (TBHP) can be used as an environmentally benign oxidant and a wide range of substrates react to give the corresponding α‐acyloxycarbonyl compounds in good to excellent yields.
它是碘:分子内和分子间标题反应是由原位生成的亚碘铵(次同)催化的。H 2 O 2或叔丁基氢过氧化物(TBHP)都可以用作环境友好的氧化剂,并且多种底物反应生成相应的α-酰氧基羰基化合物,收率良好至优异。
Selective Intermolecular Oxidative Cross-Coupling of Enolates
Selective intermolecularoxidative cross-coupling of enolates, which is a bond-forming reaction between carbanion equivalents, remains as an unsolved issue despite its potential utility for the direct synthesis of unsymmetrical 1,4-diones. The main difficulty derives from the unavoidable homo-coupling. Our strategy depends on the selective one-electron oxidation of one enolate to afford an electrophilic
Sodium Iodide-Catalyzed Direct α-Alkoxylation of Ketones with Alcohols<i>via</i>Oxidation of α-Iodo Ketone Intermediates
作者:Cuiju Zhu、Yuanfei Zhang、Huaiqing Zhao、Shijun Huang、Min Zhang、Weiping Su
DOI:10.1002/adsc.201500006
日期:2015.2.9
AbstractThe direct α‐alkoxylation of ketones with alcohols via a sodium iodide‐catalyzed oxidative cross‐coupling has been developed. This protocol enables a range of alkyl aryl ketones to cross‐couple with an array of alcohols in synthetically useful yields. The mechanistic studies provided solid evidence supporting that an α‐iodo ketone was a key reaction intermediate, being converted into an α‐alkoxylated ketone via further oxidation to a hypervalent iodine species rather than a common nucleophilic substitution, and was generated from the ketone starting material via a radical intermediate. These new mechanism insights should have an effect on the design of iodide‐catalyzed oxidative cross‐coupling reactions between nucleophiles.magnified image
Access to functionalized cyclopropylcarbinyl compounds from homoallylic ethers via zirconocene intermediates
作者:Jean-Luc Vasse、Jan Szymoniak
DOI:10.1016/j.tetlet.2004.06.122
日期:2004.8
Cyclopropylcarbinylzirconium complexes were generated from homoallylic ethers and zirconocene (CP2ZrCl2/2n-BuLi). They underwent further in situ transformations that is, bromination-substitution, transmetallation-functionalization and insertion reactions to afford various cyclopropylcarbinyl derivatives. In contrast, ring-opening products could be selectively obtained by treating the zirconium complex with MeLi, prior to functionalization. (C) 2004 Elsevier Ltd. All rights reserved.