不对称的 1,1,2-三酰基烯烃是通过 1,3-酮酯与末端炔烃的氧化偶联,在 0 °C 下使用 4.0 当量廉价的硝酸铈铵 (CAN) 作为氧化剂,以乙腈为溶剂,方便地制备的。该方法比以前报道的方法更温和,并且可以在空气中进行,从而证明了它在制备这些有用的构件方面的实用性和多功能性。该反应被认为是通过由 CAN 引发的 1,3-酮酯底物的单电子转移过程发生的,以产生 α-自由基物质,该物质迅速添加到反应中的末端炔烃伴侣。随后通过空气和 CAN 对所得乙烯基自由基进行氧化,然后导致形成作为 E 和 Z 异构体混合物的三酰基烯烃产物。反应被证明是一般的,
Formation of Unsymmetrical 1,4-Enediones via A Focusing Domino Strategy: Cross-Coupling of 1,3-Dicarbonyl Compounds and Methyl Ketones or Terminal Aryl Alkenes
A highly efficient synthesis of unsymmetrical 1,4-enediones from 1,3-dicarbonyl compounds and methyl ketones or terminalarylalkenes has been developed via a focusing domino strategy. Simple and readily available starting materials, mild reaction conditions, and a very simple operation are advantages of the reaction, which allow straightforward synthesis of a variety of unsymmetrical 1,4-enediones
An efficient manganese oxide octahedral molecular sieves OMS-2-catalyzed chemoselective synthesis of 1,4-enediones and 1,4-diketones from 1,3-dicarbonyls and alpha-iodoacetophenones is described. The present catalytic system can be applied in one-pot, three-component reactions of methyl ketones, 1,3-dicarbonyls and iodine. Moreover, OMS-2 can be reused at least 5 times without loss of activity. (C) 2015 Elsevier B.V. All rights reserved.