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
Late‐Stage Halogenation of Peptides, Drugs and (Hetero)aromatic Compounds with a Nucleophilic Hydrazide Catalyst
作者:Haripriyo Mondal、Subimal Patra、Shuvendu Saha、Tarak Nayak、Uddalak Sengupta、Modhu Sudan Maji
DOI:10.1002/anie.202312597
日期:2023.12.18
A hydrazide catalyst is introduced for the late-stage halogenation of peptides, drugs and (hetero)aromatics with high efficiency and selectivity. The active site comprises the hydrazide group attached to a sulfonamide moiety, which facilitates the acceptance as well as delivery of halonium species from the N-halosuccinimide source to the substrates, thus featuring a cooperative interaction.
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