URCOM, EA,CNRS, FR, Université du Havre, Le Havre, France.
Chemistry. 2012 Oct 29;18(44):14192-200. doi: 10.1002/chem.201202225. Epub 2012 Sep 20.
Gold catalysts have been applied in cascade-type reactions for the synthesis of different nitrogen-based compounds. The reactions likely proceed by a new gold-catalyzed cascade intermolecular α-amidoalkylation/intramolecular carbocyclization cascade process by unifying both the σ- and π-Lewis acid properties of the gold salts. In the first part of this report we show that the σ-Lewis acidity of gold(I) and gold(III) could be exploited to efficiently catalyze the nucleophilic substitution of various alkoxy- and acetoxylactams. The reaction was found to be applicable to a wide range of cyclic N-acyliminium ion precursors and various nucleophiles, including allyltrimethylsilane, silyl enol ethers, arenes, and active methylene derivatives. As a logical progression of this study, a combined hard/soft binary catalytic gold system was then used to implement an unprecedented tandem intermolecular Friedel-Crafts amidoalkylation/intramolecular hydroarylation sequence allowing an expedient access to new, complex, fused polyheterocyclic structures from trivial materials.
金催化剂已被应用于级联型反应中，用于合成不同的含氮化合物。这些反应可能通过一种新的金催化级联分子间α-酰胺烷基化/分子内环化级联反应过程进行，该过程统一了金盐的σ-和π-Lewis 酸性质。在本报告的第一部分中，我们表明金（I）和金（III）的σ-Lewis 酸性可用于有效地催化各种烷氧基和乙酰氧基内酰胺的亲核取代反应。该反应适用于广泛的环状 N-酰亚胺离子前体和各种亲核试剂，包括烯丙基三甲基硅烷、硅烯醇醚、芳基和活性亚甲基衍生物。作为这项研究的逻辑进展，然后使用组合的硬/软双催化金体系来实现前所未有的串联分子间Friedel-Crafts 酰胺烷基化/分子内环化序列，从而从普通材料中快速获得新的、复杂的稠合多杂环结构。
