Copper-catalyzed aromatic C–H bond halogenation with lithium halides under aerobic conditions
作者:Song Mo、Yamin Zhu、Zengming Shen
DOI:10.1039/c3ob40185e
日期:——
A concise and practical Cu-catalyzed protocol for the preparation of chloro- and bromoarenes via C–H bond activation has been developed. The advantages of this strategy are the employment of cheap Cu(NO3)2·3H2O, LiX and O2, and its compatibility with both electron-donating and electron-withdrawing substituents on aryl rings.
Ligandless Nickel-Catalyzed <i>Ortho</i>-Selective Directed Trifluoromethylthiolation of Aryl Chlorides and Bromides Using AgSCF<sub>3</sub>
作者:Tin Nguyen、Weiling Chiu、Xinying Wang、Madeleine O. Sattler、Jennifer A. Love
DOI:10.1021/acs.orglett.6b02689
日期:2016.11.4
A mild protocol for Ni-catalyzed trifluoromethylthiolation of aryl chlorides and bromides is described herein. The method utilizes AgSCF3 as an easily accessible nucleophilic trifluoromethylthiolating reagent and does not require any ligands or additives. Ortho-selectivity is achieved using a variety of directing groups such as imines, pyridines, and oxazolines for 24 examples in up to 95% yield.
In this work, we report the first use of a salen-based hypercrosslinked polymer-supportedPdcatalyst to carry out C-H halogenation. This catalyst can effectively catalyze C-H bromination and chlorination even better than its homogeneous counterpart Pd(OAc)2. It also showed excellent reusability without loss of catalytic activity for ten cycles. A broad substrate scope was explored and moderate to