Cerium-Catalyzed, Aerobic Oxidative Synthesis of 1,2-Dioxane Derivatives from Styrene and Their Fragmentation into 1,4-Dicarbonyl Compounds
作者:Michael Rössle、Thomas Werner、Wolfgang Frey、Jens Christoffers
DOI:10.1002/ejoc.200500487
日期:2005.12
1,4-Diketones were prepared by cerium-catalyzed oxidative coupling of styrene with molecular oxygen and 1,3-dicarbonyl compounds. This two-step sequence was performed as a one-pot procedure without isolation of the intermediate products. The first step is a metal-catalyzed radical reaction yielding 3-hydroxy-1,2-dioxane derivatives being the cyclotautomers of initially formed 4-hydroperoxy ketones
1,4-二酮是通过铈催化的苯乙烯与分子氧和1,3-二羰基化合物的氧化偶联制备的。这个两步序列是作为一锅法进行的,没有分离中间产物。第一步是金属催化的自由基反应,产生 3-羟基-1,2-二恶烷衍生物,即最初形成的 4-氢过氧酮的环互变异构体。在该序列的第二步中,这些内过氧化物通过 Kornblum-DeLaMare 断裂与 AcCl-吡啶转化为 1,4-二羰基基序。几种中间体 1,2-二恶烷衍生物可以被分离出来,并通过 X 射线晶体学进行结构表征。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)