83026-49-7Relevant 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
Synthesis of 2-Substituted 2-Arylmalonates via Tricarbonylchromium Complexes
Deutsch,Bartoszek,Schneider,Zabel,Niclas
, p. 261 - 265 (2007/10/03)
Tricarbonylchromium complexes 1 react with monosubstituted malonic acid esters 2 in DMSO at room temperature in the presence of KOtBu to give the complexes 3. After oxidative demetalation, the appropriate aryl derivatives 4 are obtained in moderate to good overall yields. Diastereoselective arylations of chirally modified malonates such as 5a-c were studied. The stereoselectivity was highest for the products 6c/6c′ (80:20) with (-)-8-phenylmenthol as alcohol component in the malonate 5.
Ester Enolates from α-Acetoxy Esters. Synthesis of Aryl Malonic and α-Aryl Alkanoic Esters from Aryl Nucleophiles and α-Keto Esters
Ghosh, Subrata,Pardo, Simon N.,Salomon, Robert G.
, p. 4692 - 4702 (2007/10/02)
Ester enolates are generated by reductive α-deacetoxylation of α-acetoxy-α-arylmalonic esters or α-acetoxy-α-arylalkanoic esters with lithium in liquid ammonia or sodium α-(dimethylamino)naphthalenide in hexamethylphosphoramide-benzene.Since the requisite α-acetoxy esters are available from aryl nucleophiles, the reductions provide effective new synthetic routes to arylmalonic esters and α-arylalkanoic esters.For example, 2-(p-isobutylphenyl)propionic acid (ibuprofen, a commercially important nonsteroidal antiinflammatory agent) is obtained in 73percent yield overall from isobutylbenzene.Arenes, aryllithiums, or arylmagnesium halides react with α-keto esters, e.g., diethyl oxomalonate, ethyl pyruvate, methyl phenylglyoxalate, or alkyl glyoxylates, to afford α-hydroxy esters.These are acetylated with acetic anhydride-triethylamine and p-(dimethylamino)pyridine as a catalyst.Reductive α-deoxygenation then allows replacement of the acetoxy group by hydrogen or an alkyl group.
