Copper-catalyzed oxidative synthesis of 2-oxo-acetamidines from one-pot three-component reaction of aryl methyl ketones,secondary amines and anilines

Some novel 2-oxo-acetamidines were synthesized via one-pot three-component reaction of acetophenones, secondary amines and anilines in presence of CuI as catalyst. The reaction involved in a oxidation process of C (sp³)H bonds of acetophenones in presence of air followed by aminations, and products were obtained in good to excellent yields (70–82%) in simple work-up procedure.     

A new tandem reaction of benzyne: one-pot synthesis of aryl amines containing anthracene

[reaction: see text] The reaction of benzyne with N-substituted imidazoles affords a novel way to prepare arylamines containing anthracene under very mild conditions. This transformation is assumed to proceed via a tandem reaction involving a Diels-Alder reaction and an intermolecular nucleophilic coupling reaction.     

Iodine-mediated one-pot synthesis of C-3 acylated indolizines from pyridines,aryl methyl ketones and acrylate derivatives

An I₂/CuI-promoted multi-component reaction from pyridines, aryl methyl ketones and electron deficient acrylates has been accomplished in a “one-pot” manner, which provides a straightforward and efficient access to C-3 acylated indolizines. The key intermediate of N-ylides is hypothesized to be generated in situ from pyridines and (hetero)aryl methyl ketones in the presence of iodine. This method has been applied in the synthesis of two molecules with anticonvulsant and anti-inflammatory activities.     

Microwave-assisted selenium dioxide oxidation of aryl methyl ketones to aryl glyoxals

We report an improved procedure for the synthesis of phenyl glyoxal and a series of para-substituted aryl glyoxals by microwave-assisted selenium dioxide oxidation. The reaction time has been reduced from several hours to three minutes for activated aryl methyl ketone substrates and 18 min for deactivated substrates, with all reactions affording quantitative conversion into the corresponding aryl glyoxals.     

Synthesis of 2-arylacrylic esters from aryl methyl ketones via Wittig reaction/singlet oxygen ene reaction

An efficient synthetic method has been developed for the synthesis of 2-arylacrylic esters from the corresponding aryl methyl ketones via Wittig reaction and singlet oxygen ene reaction. Wittig reaction to aryl methyl ketones with (methoxymethyl)triphenylphosphonium chloride in basic condition afforded the methyl enol ethers, and then 2-arylacrylic esters were obtained by singlet oxygen ene reaction, followed by tosylation and elimination in one-pot to the methyl enol ethers in good yields.     

Synthesis of substituted quinoline via copper-catalyzed one-pot cascade reactions of 2-bromobenzaldehydes with aryl methyl ketones and aqueous ammonia

In this Letter, a new version of the Friedländer synthesis of quinoline derivatives starting from 2-bromobenzaldehydes, aryl methyl ketones, and aqueous ammonia with copper-catalyzed amination as a key step is presented. Remarkable advantages of this new quinoline synthesis include commercially available and economical starting materials, simple operational process, and excellent efficiency.     

Investigation of the chemical heterogeneity of polyphenylenes using the condensation of methyl aryl ketones as a model reaction

The chemical heterogeneity of polyphenylenes obtained by trimerization poiycycio-condensation of acetylaromatic compounds has been investigated by GLC-MS analysis of the products of trimerization cyclocondensation of acetophenone. The mechanism for the formation of side products of the reaction is discussed. The presence of dypnone fragments in the polyphenylene structure results in a decrease in the thermal stability of these polymers.Deceased March, 1993.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1595–1601, September, 1993.     

Novel two step synthesis of pyrazoles and isoxazoles from aryl methyl ketones

Various acetyl aromatics when reacted with dimethylformamide dimethyl acetal gave 1-aryl-3-dimethylamino-2-propen-1-ones. These intermediates are masked β-ketoaldehydes and react with hydrazine hydrate or hydroxylamine at room temperature to give in good yields pyrazoles or isoxazoles.     

Synthesis of heteroaryl ketones via tandem reaction of 1,1-dibromoethenes

A novel method for the synthesis of heteroaryl ketones through one-pot tandem reaction of 1,1-dibromoethenes with 2-amino(thio)phenols promoted by TBAF·3H₂O and RuCl₃(5%)/air was developed. This novel method includes several reactions in one-pot and utilizes economical yet efficient reagents to generate synthetically and biologically interesting heteroaryl ketones under mild conditions with good efficiency.     

Rhodium-catalyzed cleavage reaction of aryl methyl ethers with thioesters

A rhodium complex catalyzed the reaction of aryl methyl ethers and thioesters giving the corresponding aryl esters and methyl sulfides. S-(p-Chlorophenyl) p-(dimethylamino)benzothioate was used for the reaction of methyl aryl ethers with electron-withdrawing groups, and an S-(p-tolyl) derivative was used for those with electron-donating groups. Polymethoxybenzenes were converted to the esters in a regioselective manner.     

Regiospecific organocatalytic asymmetric aldol reaction of methyl ketones and alpha,beta-unsaturated trifluoromethyl ketones

[structure: see text]. The aldol reaction of methyl ketones and alpha,beta-unsaturated trifluoromethyl ketones occurred under mild conditions with the combination of proline-derived N-sulfonylamide and trifluoroacetic acid as the catalyst to give the corresponding unsaturated alpha-trifluoromethyl tertiary alcohols in high yields with good enatioselectivities.     

Synthesis of polycyclic benzonitriles via a one-pot aryl alkylation/cyanation reaction

A norbornene-mediated palladium-catalyzed tandem alkylation/cyanation sequence is described in which an alkyl-aryl bond and a nitrile-aryl bond are formed in one pot. A variety of sterically hindered, five-, six-, and seven-membered ring benzonitriles were synthesized in good yields from easily accessible starting materials.     

Direct asymmetric aldol reaction of aryl ketones with aryl aldehydes catalyzed by chiral BINOL-derived zincate catalyst

Direct asymmetric aldol reaction of aryl ketones with aryl aldehydes catalyzed by chiral metal complex is reported for the first time herein. Two novel semicrown chiral ligands 1a and 1b were synthesized from (S)- and (R)-BINOL, respectively, and then employed to catalyze the direct asymmetric aldol addition of aryl ketones to aryl aldehydes. Introduced with 2.0 equiv of diethylzinc, 1b had higher enantioselectivity than 1a. Up to 97% yield and up to 80% enantioselectivity were achieved.     

Electrocatalytic haloform reaction - conversion of methyl ketones to methyl esters of carboxylic acids

An electrocatalytic haloform reaction is accomplished. Methyl ketones are converted to the corresponding carboxylic acid methyl esters in a diaphragmless electrolyzer in methanol in the presence of catalytic quantities of NaBr. The methyl ester of 3-phenylpropanoic acid is formed from benzyl methyl ketone under these conditions via electrochemically induced Favorskii rearrangement.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 122–126, January, 1991.     

A facile method for the stereoselective Horner-Wadsworth-Emmons reaction of aryl alkyl ketones

Excellent Z or E selectivity was observed in the Horner-Wadsworth-Emmons (HWE) reactions of methyl bis(2,2,2-trifluoroethyl)phosphonoacetate or ethyl 2-fluoro-2-diethylphosphonoacetate with aryl alkyl ketones bearing substituents on an aromatic moiety employing Sn(OSO2CF3)2 in the presence of N-ethylpiperidine.     

(S)-Pyrrolidine sulfonamide catalyzed asymmetric direct aldol reactions of aryl methyl ketones with aryl aldehydes

A (S)-pyrrolidine sulfonamide catalyzed asymmetric direct aldol reaction of aryl methyl ketones with aromatic aldehydes has been developed with moderate to good enantioselectivities. The study considerably broadens the substrate scope of chiral amines promoted aldol processes.     

Synthesis of benzocycloalkene derivatives via Pd-catalyzed one-pot two-step reactions of benzocyclic ketones,tosylhydrazide with aryl bromides

A new method for the synthesis of benzocycloalkene derivatives is described, through the palladium-catalyzed one-pot two-step reactions of benzocyclic ketones, tosylhydrazide with aryl bromides. Palladium-carbene complex as an important intermediate undergoes migratory insertion to form benzylpalladium complex, followed by a fast β-hydride elimination to give substituted benzocycloalkenes. The advantages of this reaction include readily available starting materials, broad substrate scope, high efficiency, and gram scale synthesis.     

A one-pot asymmetric organocatalytic tandem reaction for the synthesis of oxazine derivatives

An easy one-pot tandem reaction catalyzed by a chiral secondary amine for the synthesis of optically active oxazine derivatives has been performed and the corresponding substituted benzo[d]pyrido[2,1-b][1,3]oxazine derivatives were afforded in generally high yields (up to 99%) and excellent enantioselectivities (up to >99%).     

Aluminum enolates via retroaldol reaction: catalytic tandem aldol-transfer—Tischtschenko reaction of aldehydes with aldol adducts of ketones to ketones

Bidentate aluminum chelates derived from biphenol, binaphthol and catechol were found to be efficient catalysts for aldol-transfer reactions of ketone to ketone aldol adducts with aliphatic or aromatic aldehydes giving rise to the formation of aldol adducts of ketones to the aldehydes. In the presence of an excess of an aliphatic aldehyde, a catalytic tandem aldol-transfer—Tischtschenko reaction is observed. The tandem reaction produces monoesters of 1,3-diols with high anti selectivity and with modest to good chemical yield. 1,2-Unsaturated aldehydes are less reactive in the aldol-transfer reaction and require 2-4 times higher load of the catalyst to be used than aliphatic and aromatic aldehydes. Poor diastereoselectivity was observed in the formation of α-substituted aldols and 2-substituted monoesters of anti-1,3-diols indicating that the aldol-transfer reaction is not diastereoselective with the catalysts studied. The utility of the highly 1,3-anti selective formation of diolmonoesters was found to be limited by acyl migration.