25783-45-3Relevant articles and documents
Transition-Metal-Free C-C, C-O, and C-N Cross-Couplings Enabled by Light
Liu, Wenbo,Li, Jianbin,Querard, Pierre,Li, Chao-Jun
, p. 6755 - 6764 (2019/05/06)
Transition-metal-catalyzed cross-couplings to construct C-C, C-O, and C-N bonds have revolutionized chemical science. Despite great achievements, these metal catalysts also raise certain issues including their high cost, requirement of specialized ligands, sensitivity to air and moisture, and so-called "transition-metal-residue issue". Complementary strategy, which does not rely on the well-established oxidative addition, transmetalation, and reductive elimination mechanistic paradigm, would potentially eliminate all of these metal-related issues. Herein, we show that aryl triflates can be coupled with potassium aryl trifluoroborates, aliphatic alcohols, and nitriles without the assistance of metal catalysts empowered by photoenergy. Control experiments reveal that among all common aryl electrophiles only aryl triflates are competent in these couplings whereas aryl iodides and bromides cannot serve as the coupling partners. DFT calculation reveals that once converted to the aryl radical cation, aryl triflate would be more favorable to ipso substitution. Fluorescence spectroscopy and cyclic voltammetry investigations suggest that the interaction between excited acetone and aryl triflate is essential to these couplings. The results in this report are anticipated to provide new opportunities to perform cross-couplings.
Synthesis of aryl ethers from aromatic carboxylic acids
Bhadra, Sukalyan,Dzik, Wojciech I.,Goossen, Lukas J.
supporting information, p. 2387 - 2390 (2013/09/23)
A silver/copper bimetallic catalyst system promotes the decarboxylative Chan-Evans-Lam alkoxylation of ortho-substituted aromatic carboxylate salts with tetraalkyl orthosilicates or triaryl borates. Non-ortho-substituted carboxylates are alkoxylated via an ortho-C-H-alkoxylation with concomitant cleavage of the carboxylate directing group via protodecarboxylation. This way, meta-substituted carboxylates are converted into para-substituted alkoxyarenes and vice versa. The combined processes provide a convenient synthetic entry to the important class of aromatic ethers from widely available carboxylic acids.
General, mild, and intermolecular Ullmann-type synthesis of diaryl and alkyl aryl ethers catalyzed by diol-copper(I) complex
Naidu, Ajay B.,Jaseer,Sekar, Govindasamy
supporting information; experimental part, p. 3675 - 3679 (2009/09/26)
(Chemical Equation Presented) A wide range of diaryl ethers and alkyl aryl ethers are synthesized through intermolecular C(aryl)-O bond formation from the corresponding aryl iodides/aryl bromides and phenols/alcohols through Ullmann-type coupling reaction in the presence of a catalytic amount of easily available (±)-diol L3-CuI complex under very mild reaction conditions. Less reactive aryl bromides can also be used for O-arylation of phenols under the same reaction conditions without increasing the reaction temperature, catalyst loading, and time. The catalytic system not only is capable of coupling hindered substrate but also tolerates a broad range of a series of functional groups.
