Regioselective copper-catalyzed chlorination and bromination of arenes with O2 as the oxidant
作者:Lujuan Yang、Zhan Lu、Shannon S. Stahl
DOI:10.1039/b915487f
日期:——
Electron-rich aromatic C–H bonds undergo regioselective chlorination and bromination in the presence of CuX2, LiX (X = Cl, Br) and molecular oxygen. Preliminary mechanistic insights suggest that the bromination and chlorination reactions proceed by different pathways.
By the use of 1-chloro-1,2-benziodoxol-3-one, an age-old reagent, the practical and efficient chlorination method is achieved. This hypervalent iodine reagent is amenable not only to the chlorination of nitrogen-containing heterocycles but also to selected classes of arenes, BODIPY dyes, and pharmaceuticals. In addition, the advantages, such as easy preparation and recyclable, air- and moisture-stable
Electrophilic halogenation is used to produce a wide variety of halogenated compounds. Previously reported methods have been developed mainly using a reagent‐based approach. Unfortunately, a suitable “catalytic” process for halogen transfer reactions has yet to be achieved. In this study, arylamines have been found to generate an N‐halo arylamine intermediate, which acts as a highly reactive but selective catalytic
Oxidative functionalization of indoles is one of the most widely used approaches to exploit the synthetic utility of indoles. In continuation of our research interest in the green oxidation of indoles, we further explore the oxidation of indoles with oxone–halide and discover that the protecting group on the nitrogen of indoles plays a decisive role in controlling the pathways of indoleoxidation with
Dabco-catalysed selective chlorination of aromatics
作者:Jun Xu、Xue Li、Qiji Li、Weiyi Tian、Xiaosheng Yang
DOI:10.1016/j.tetlet.2024.154928
日期:2024.2
A Lewis base catalyst DABCO for highly efficient electrophilic aromatic chlorination using NCS was presented. The mild conditions, easy-availability and stability of the catalyst and reagents, as well as good functional-group tolerance, showed the approach to be a versatile protocol for the late-stage aromatic chlorination of complex natural products and drugs.