Carboxyl radical-assisted 1,5-aryl migration through Smiles rearrangement
作者:Asik Hossian、Ranjan Jana
DOI:10.1039/c6ob01758d
日期:——
We report herein, a silver(I)-catalyzed Smiles rearrangement of 2-aryloxy- or 2-(arylthio)benzoic acids to provide aryl-2-hydroxybenzoate or aryl-2-mercaptobenzoate dimer, respectively, through 1,5-aryl migration from oxygen or sulfur to carboxylate oxygen. Mechanistically, the aryl ether moiety undergoes an intramolecular ipso attack by the carboxyl radical followed by a C–O or C–S bond cleavage.
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
Synthesis of salicylates from anionically activated aromatic trifluoromethyl group
作者:Huilin Xie、Chuankai Lin、Ruixiang Wang、Jin-Biao Liu
DOI:10.1016/j.tetlet.2021.153592
日期:2022.1
An efficient approach to salicylates via a novel transformation of anionically activated aromatic trifluoromethylgroup is described. Anionically activated trifluoromethylgroup can react with phenols/alcohols under alkaline conditions to afford aryl/alkyl salicylates in high yields. Mechanism studies indicate that the carbonyl oxygen atom of ester is from the H2O in the solvent.
We report herein a cerium photocatalyzed aryl migration from an aryl ether to a carboxylic acid group through radical-Smiles rearrangement. This operationally simple protocol utilizes inexpensive CeCl3 as a photocatalyst and converted a variety of 2-aryloxybenzoic acids into aryl-2-hydroxybenzoates in good yields.
N-Heterocyclic carbene/photo-cocatalyzed oxidative Smiles rearrangement: synthesis of aryl salicylates from <i>O</i>-aryl salicylaldehydes
作者:Zi-Hao Xia、Lei Dai、Zhong-Hua Gao、Song Ye
DOI:10.1039/c9cc09272b
日期:——
The N-heterocyclic carbene/photo-cocatalyzed oxidative Smiles rearrangement of O-aryl salicylaldehydes was developed. Both electron-deficient and electron-rich aryls worked well as migrating groups, giving the corresponding aryl salicylates in good yields. This reaction features formation of two new C-O bonds and one C-O bond cleavage via metal-free oxidation of the Breslow intermediate using oxygen