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 benzoates through carboxylate-directed C-H-activating alkoxylation with concomitant protodecarboxylation
Bhadra, Sukalyan,Dzik, Wojciech I.,Goo?en, Lukas J.
, p. 2959 - 2962 (2013/04/10)
One in, one out: In the presence of a copper/silver bimetallic catalyst system, aromatic carboxylate salts undergo ortho C-H alkoxylation with concomitant loss of the carboxylate directing group in a protodecarboxylation step (see scheme, FG=functional group). This process provides a convenient synthetic access to the important class of aromatic ethers from widely available carboxylic acids. Copyright
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.
Insertion of arynes into the carbon-oxygen double bond of amides and its application into the sequential reactions
Yoshioka, Eito,Miyabe, Hideto
experimental part, p. 179 - 189 (2012/02/15)
The reaction of arynes, generated from ortho-(trimethylsilyl)aryl triflates, with the CO bond of formamides gave salicylaldehyde derivatives via the formation of formal [2+2] adducts. The sequential transformation of arynes into ortho-disubstituted arenes, o-aminoalkylphenols or o-hydroxyalkylphenols, was achieved by one-pot procedure using dialkylzincs.
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.
An efficient intermolecular BINAM-copper(I) catalyzed Ullmann-type coupling of aryl iodides/bromides with aliphatic alcohols
Naidu, Ajay B.,Sekar
, p. 3147 - 3151 (2008/09/20)
A wide range of alkyl aryl ethers are synthesized from the corresponding aryl iodides and aliphatic alcohols through Ullmann-type intermolecular coupling reactions in the presence of a catalytic amount of easily available BINAM-CuI complex. Less reactive aryl bromides have also been shown to react with aliphatic alcohols under identical reaction conditions to give good yields of the alkyl aryl ethers without increasing the reaction temperature and time.
Arenediazonium o-benzenedisulfonimides as efficient reagents for Heck-type arylation reactions
Artuso, Emma,Barbero, Margherita,Degani, Iacopo,Dughera, Stefano,Fochi, Rita
, p. 3146 - 3157 (2007/10/03)
Arenediazonium o-benzenedisulfonimides can be used as new and efficient reagents for Heck-type arylation reactions of some common substrates containing C-C multiple bonds, namely ethyl acrylate, acrylic acid, acroleyne, styrene and cyclopentene. The reactions were carried out in an organic solvent, in the presence of Pd(OAc)2 as pre-catalyst, and gave rise to arylated products, for example, ethyl cinnamates, cinnamic acids, cinnamic aldehydes and stilbenes, possessing an (E)-configuration, and 1-arylcyclopentenes, in good to excellent yields. It is noteworthy that all the reactions led to the recovery, in greater than 80% yield, of o-benzenedisulfonimide, recyclable for the preparation of other diazonium salts.
Copper-catalyzed formation of carbon-heteroatom and carbon-carbon bonds
-
, (2015/03/06)
The present invention relates to copper-catalyzed carbon-heteroatom and carbon-carbon bond-forming methods. In certain embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-nitrogen bond between the nitrogen atom of an amide or amine moiety and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In additional embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-nitrogen bond between a nitrogen atom of an acyl hydrazine and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In other embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-nitrogen bond between the nitrogen atom of a nitrogen-containing heteroaromatic, e.g., indole, pyrazole, and indazole, and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In certain embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-oxygen bond between the oxygen atom of an alcohol and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. The present invention also relates to copper-catalyzed methods of forming a carbon-carbon bond between a reactant comprising a nucleophilic carbon atom, e.g., an enolate or malonate anion, and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. Importantly, all the methods of the present invention are relatively inexpensive to practice due to the low cost of the copper comprised by the catalysts.
A product analytical study of the thermal and photolytic decomposition of some arenediazonium salts in solution
Canning, Peter S. J.,Maskill, Howard,McCrudden, Katharine,Sexton, Brian
, p. 789 - 800 (2007/10/03)
Products of thermal and photochemical reactions of eleven arenediazonium tetrafluoroborates in various solvents have been analyzed. All compounds in most solvents undergo unimolecular heterolysis to give singlet aryl cations which are captured by solvent. This mechanism is dominant for arenediazonium ions without electron-withdrawing substituents in all solvents, and the only reaction observed in water. Additionally, appreciable yields of fluoroarenes are obtained by fluoride abstraction by the aryl cation from fluorinated solvents and from tetrafluoroborate in fluorinated solvents. Yields from photochemical processes are very similar to those from thermal reactions indicating that the main reactions proceed through common or very similar intermediates. Aryl cations formed from ion-paired diazonium ions may react with the counterion, but fragmentation of dissociated diazonium ions leads only to solvent-derived product. Some arenediazonium ions in some solvents undergo an alternative radical reaction leading principally to hydrodediazoniation. It is proposed that this reaction involves initial rate-limiting electron transfer from ethanol to the arenediazonium ion followed rapidly by homolysis of the resultant aryldiazenyl radical. Within the same solvent cage, the aryl radical then either abstracts an α-hydrogen from the ethanol radical cation generated in the first step to give the reduction product and protonated acetaldehyde, or combines with it at the oxygen to give a protonated aryl ethyl ether.
Copper-catalyzed coupling of aryl iodides with aliphatic alcohols.
Wolter, Martina,Nordmann, Gero,Job, Gabriel E,Buchwald, Stephen L
, p. 973 - 976 (2007/10/03)
[reaction: see text] A simple and mild method for the coupling of aryl iodides and aliphatic alcohols that does not require the use of alkoxide bases is described. The reactions can be performed in neat alcohol. For more precious alcohols, the etherificat
