74610-81-4Relevant academic research and scientific papers
Arylation with unsymmetrical diaryliodonium salts: A chemoselectivity study
Malmgren, Joel,Santoro, Stefano,Jalalian, Nazli,Himo, Fahmi,Olofsson, Berit
supporting information, p. 10334 - 10342 (2013/09/02)
Phenols, anilines, and malonates have been arylated under metal-free conditions with twelve aryl(phenyl)iodonium salts in a systematic chemoselectivity study. A new "anti-ortho effect" has been identified in the arylation of malonates. Several "dummy groups" have been found that give complete chemoselectivity in the transfer of the phenyl moiety, irrespective of the nucleophile. An aryl exchange in the diaryliodonium salts has been observed under certain arylation conditions. DFT calculations have been performed to investigate the reaction mechanism and to elucidate the origins of the observed selectivities. These results are expected to facilitate the design of chiral diaryliodonium salts and the development of catalytic arylation reactions that are based on these sustainable and metal-free reagents. Copyright
Palladium-catalyzed arylation of malonates and cyanoesters using sterically hindered trialkyl- and ferrocenyldialkylphosphine ligands
Beare, Neil A.,Hartwig, John F.
, p. 541 - 555 (2007/10/03)
Palladium-catalyzed reactions of aryl bromides and chlorides with two common stabilized carbanions - enolates of dialkyl malonates and alkyl cyanoesters - are reported. An exploration of the scope of these reactions was conducted, and the processes were shown to occur in a general fashion. Using P(t-Bu)3 (1), the pentaphenylferrocenyl ligand (Ph5C5)Fe(C5H4)P(t-Bu) 2 (2), or the adamantyl ligand (1-Ad)P(t-Bu)2 (3), reactions of electron-poor and electron-rich, sterically hindered and unhindered aryl bromides and chlorides were shown to react with diethyl malonate, di-tertbutyl malonate, diethyl fluoromalonate, ethyl cyanoacetate, and ethyl phenylcyanoacetate. Although alkyl malonates and ethyl alkylcyanoacetates did not react with aryl halides using these catalysts, the same products were formed conveniently in one pot from diethylmalonate by cross-coupling of an aryl halide in the presence of excess base and subsequent alkylation.
Oxidation of Malonic Acid Derivatives by Manganese(III) Acetate. Aromatic Malonylation Reaction. Scope and Limitations
Citterio, Attilio,Santi, Roberto,Fiorani, Tiziana,Strologo, Sauro
, p. 2703 - 2712 (2007/10/02)
The oxidation of malonic acid derivatives RCH(COOR1)COOR2 (R1 = or R2 = H, Me, Et; R = H, Me, Et, n-Bu, i-Pr, C6H5, 4-OMeC6H4) by anhydrous or dihydrated manganese(III) acetate was studied in acetic acid in the presence of aromatic substrates at 20-80 deg C, generally with stoichiometric amounts of reagents.Electron-rich aromatics (IP 7.5 eV) underwent nuclear acetoxylation or quinone formation, the process being exclusive with anthracene and competitive with nuclear malonylation for 1- and 2-methoxynaphthalene.With other less electron-rich substrates (IP 8.5 eV) only the products coming from the oxidation of the malonic acid derivatives (aryl malonates, tartronates, etc., or dimerization and disproportionation products) were observed.The selectivity and the yield of aromatic substitution by the malonyl group was found to be affected by the electron density of the aromatic ring, the steric inhibition of substituents in the Mn(III) oxidation of the malonic acid derivative, the oxidizability of malonyl radical by Mn(III), the base (acetate ions or water) eventually present in the medium, and the further easy oxidation of the primary aryl malonate product, when unsubstituted dialkylmalonates or malonic acid were used.A mechanism is suggested in which inner-sphere electron transfer from Mn(III)-malonate complex affords Mn(II) malonyl radicals that are partitioned between oxidation, dimerization (or disproportionation), and reversible addition to the aromatics.
The Chemistry of Aryllead(IV) Tricarboxylates. Reaction with Derivatives of Malonic Acid: New Routes to α-Aryl Carboxylic Acids and Arylated Barbituric Acid Derivatives
Kopinski, Richard P.,Pinhey, John T.,Rowe, Bruce A.
, p. 1245 - 1254 (2007/10/02)
Derivatives of 2,2-dimethyl-1,3-dioxan-4,6-dione (Meldrum's acid) and the sodium salts of substituted malonic esters undergo electrophilic C-arylation in high yield with aryllead triacetates, thus providing new routes to α-arylalkanoic acids.Syntheses of the antiflammatory compound 2-(p-isobutylphenyl)propanoic acid (Ibuprofen) have been carried out to demonstrate the method.The arylation reaction has been extended to 5-ethylbarbituric acid and to barbituric acid itself, which affords the 5,5-diarylated derivatives in good yield.A study of the effect of some tertiary bases on the reaction of p-methoxyphenyllead triacetate with the 5-isopropyl derivative of Meldrum's acid has shown that replacement of pyridine by 2,2'-bipyridyl results in an increase in yield and reaction rate, while a further marked improvement occurs in the presence of 1,10-phenanthroline.
THE α-ARYLATION OF DERIVATIVES OF MALONIC ACID WITH ARYLLEAD TRIACETATES. NEW SYNTHESES OF IBUPROFEN AND PHENOBARBITAL.
Pinhey, John T.,Rowe, Bruce A.
, p. 965 - 968 (2007/10/02)
Derivatives of Meldrum's acid and the sodium salts of substituted malonic acid esters undergo rapid arylation in high yield when treated with aryllead triacetates.These reactions have been applied to the synthesis of ibuprofen, an analgesic, and in a closely related reaction 5-ethylbarbituric acid has been reacted with phenyllead triacetate to give phenobarbital.
