Koy Maximilian, Sandfort Frederik, Tlahuext-Aca Adrian, Quach Linda, Daniliuc Constantin G, Glorius Frank
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149, Münster, Germany.
Chemistry. 2018 Mar 26;24(18):4552-4555. doi: 10.1002/chem.201800813. Epub 2018 Mar 9.
The palladium-catalyzed coupling reaction of N-hydroxyphthalimide esters and styrenes to deliver exclusively (E)-substituted olefins under irradiation with visible light is reported. This method tolerates N-hydroxyphthalimide esters derived from primary, secondary, tertiary as well as benzylic carboxylic acids. Notably, Pd(PPh ) is employed as an inexpensive palladium source and no addition of base or classical photocatalyst is required. Mechanistic studies suggest a light-mediated single-electron reduction of the activated acid by a photoexcited palladium(0) species to access alkyl radicals through decarboxylation.
据报道,在可见光照射下,N-羟基邻苯二甲酰亚胺酯与苯乙烯发生钯催化偶联反应,专一性地生成(E)-取代烯烃。该方法适用于由伯、仲、叔羧酸以及苄基羧酸衍生的N-羟基邻苯二甲酰亚胺酯。值得注意的是,使用Pd(PPh₃)₄作为廉价的钯源,无需添加碱或传统光催化剂。机理研究表明,光激发的钯(0)物种对活化酸进行光介导的单电子还原,通过脱羧作用生成烷基自由基。