Heck Reactions without Salt Formation: Aromatic Carboxylic Anhydrides as Arylating Agents
摘要:
Environmentally benign and economical production of arylated olefins can be achieved by a new variant of the Heck reaction in which no halogen salts are formed. The trick is the use of aromatic carboxylic anhydrides 1 as arylating agents. With halide-activated palladium chloride as catalyst, which requires no phosphane ligands, the olefins 2 can be prepared according to Equation (a) in good yields.
is a powerful tool for the olefination of arenes by Pd-catalysed C–H activation. However, the need for superstoichiometric amounts of toxic chemical oxidants makes the reaction unattractive from an environmental and atom-economical view. Herein, we report the first non-directed and regioselective olefination of simple arenes via an electrooxidative Fujiwara–Moritani reaction. The versatility of this
Fujiwara-Moritani 反应是通过 Pd 催化的 C-H 活化进行芳烃烯化的有力工具。然而,由于需要超化学计量的有毒化学氧化剂,因此从环境和原子经济角度来看,该反应没有吸引力。在此,我们报告了通过电氧化藤原-森谷反应实现简单芳烃的第一个非定向和区域选择性烯化。这种操作友好的方法的多功能性通过广泛的底物范围得到了证明,其中包括芳烃、杂芳烃和各种烯烃。电分析研究表明 Pd( II )/Pd( IV ) 催化循环通过Pd( III ) 中间体参与。