A 2,2′-bipyridine-palladacycle catalyzed the coupling of arylboronic acids with nitroarenes
摘要:
A novel palladium-catalyzed protocol for the synthesis of diaryl ethers derivatives has been developed. In the presence of 2,2'-bipyridine-cyclopalladated ferrocenylimine complex (Cat. Ic), diary] ethers were selectively generated by adjusting reaction parameters through the coupling of arylboronic acids and nitroarenes with yields ranging from poor to good. The efficiency of this reaction was demonstrated by its compatibility with a range of groups. Moreover, the rigorous exclusion of air or moisture was not required in these transformations. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.
A simple, metal- and ligand-free procedure for the Ullmann-type C–O coupling reactions has been achieved by allowing aryl bromides to react with a variety of phenols in the presence of t-BuOK. Moderate to excellent yields of O-arylation products are obtained under mild conditions in a short time. In addition, two examples of C–N coupling reactions are also reported. A benzyne mechanism is proposed
The first palladium‐catalyzed protocol for the denitrated coupling reaction of nitroarenes with phenols has been developed, achieving unsymmetrical diaryl ethers in moderate to excellent yields. The cyclopalladatedferrocenylimine (catalyst Ic) exhibited highly catalytic activity for this transformation with low catalyst loading (0.75 mol%) and short reaction time (2 h). The efficiency of this reaction
Efficient Aryl Migration from an Aryl Ether to a Carboxylic Acid Group To Form an Ester by Visible-Light Photoredox Catalysis
作者:Shao-Feng Wang、Xiao-Ping Cao、Yang Li
DOI:10.1002/anie.201706597
日期:2017.10.23
We have developed a highly efficient aryl migration from an arylether to a carboxylic acid group through retro‐Smiles rearrangement by visible‐light photoredox catalysis at ambient temperature. Transition metals and a stoichiometric oxidant and base are avoided in the transformation. Inspired by the high efficiency of this transformation and the fundamental importance of C−O bond cleavage, we developed
Unprecedented aryl-to-aryl 1,5-rhodium migration is involved in decyanative silylation of aryl cyanides bearing a tethered arene. The 1,5-migration proceeds through remote C-Hbondactivation. 1,5-Migration also occurs in other rhodium-catalyzed reactions, including borylation and oxidative Mizoroki-Heck reactions.
Smiles rearrangement for the synthesis of ortho-hydroxyphenyl arylketimines. Detailed examinations revealed that migration of various aromatic groups, previously considered to be unsuited to SNAr-type reactions, such as electron-rich or sterically hindered aromatic groups, can be accomplished by introducing bulky 9-anthryllithium as a nucleophile. Among the aromatic groups examined, naphthyl groups (1-