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.
We have developed an efficient Pd‐catalyzed directed C—H bromination protocol, in which dimethyl sulfoxide (DMSO) is employed as oxidant with hydrobromic acid aqueous solution (HBr(aq)) as bromide source. The DMSO/HBr(aq) system, which is novelly and efficiently utilized in transition‐metal catalyzed C—H activation, illustrates its practicability by the operational simplicity, inexpensive and readily
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
Synthesis of Quinolizinium-Type Heteroaromatics via a Carbene Intermediate
作者:Feng Li、Jihee Cho、Shenpeng Tan、Sanghee Kim
DOI:10.1021/acs.orglett.7b03964
日期:2018.2.2
An efficient synthesis of quinolizinium-type heteroaromatics by Pt(II)-catalyzed cyclization of 2-arylpyridine propargyl alcohol has been developed. The presence of a protic acid is crucial for the success of the reaction. Mechanistic studies disclosed that the reaction proceeds via a platinum–carbene intermediate. Additionally, the fluorescence properties of the synthesized heteroaromatics were investigated
Boron‐Mediated Regioselective Aromatic C−H Functionalization via an Aryl BF
<sub>2</sub>
Complex
作者:Ganesh H. Shinde、Henrik Sundén
DOI:10.1002/chem.202203505
日期:2023.2.16
Regioselectivefunctionalization of 2-aryl-azaarenes N-heteroarenes and aryl aldehydes has been achieved. The reaction proceeds via a BBr3 promoted 5 and 6-membered boracycle that undergoes a ligand exchange promoted by Selectfluor to give a previously scarce aryl BF2 species. The aryl BF2 is a bench stable intermediate that can be used for the deborylative functionalization of the 2-aryl-azaarenes