Reaction Of Α-bromoketones Research Articles

Cascade Functionalization of C(sp3)-Br/C(sp2)-H Bonds: Access to Fused Benzo[e]isoindole-1,3,5-trione via Visible-Light-Induced Reductive Radical Relay Strategy.

A reductive radical relay strategy for the construction of fused benzo[e]isoindole-1,3,5-trione through a reaction of α-bromo ketones with maleimides in the presence of Ir(ppy)3 under visible-light irradiation is described. The protocol employs very mild reaction conditions and offers satisfactory yields. Moreover, the reaction proceeds through a cascade C(sp3)-Br/C(sp2)-H functionalization, double C-C bond formation, and oxidative aromatization sequence.

Copper(II) bis-thiazole complex immobilized on silica nanoparticles: Preparation, characterization and its application as a highly efficient catalyst for click synthesis of 1,2,3-triazoles

In this work, the preparation of copper(II) complex of 3,5-bis(2-benzothiazolyl)pyridine, Cu(II)Br2-BTP, supported on nano silica functionalized with trimethoxysilylpropylchloride, Cu(II)Br2-BTP@TMSP-nSiO2, is reported. The prepared catalyst was characterized by different analytical techniques such as elemental analysis, FT-IR, 1H NMR, ICP-OES, XPS and UV–Vis spectroscopic methods, and also SEM and TEM microscopic techniques. This heterogeneous catalyst showed excellent activity in the click synthesis of 1,2,3-triazoles via one-pot three-component reaction of alkynes, organic halides, and sodium azide. Moreover, the catalyst was applied for synthesis of 1,2,3-triazoles by the reaction of α-bromoketones, alkyl/aryl terminal alkynes and sodium azide. The heterogeneous catalyst was reused several times without any decrease in its catalytic activity.

Green approach: an efficient synthesis of 2,4-disubstituted-1,3-thiazoles and selenazoles in aqueous medium under ultrasonic irradiation

An efficient and rapid procedure for the synthesis of 2,4-disubstituted-1,3-thiazoles and selenazoles has been described by the reaction of α-bromoketones with thiourea, phenylthiourea and selenourea at ambient temperature in aqueous medium under ultrasonic irradiation. Analytically pure products were formed within 10–60 s in excellent yields. The advantageous features of this non-conventional methodology over conventional methods are the operational simplicity, easy handling, yield-enhancing, time-reducing, mild reaction conditions and no by-product production.

Hepatitis C virus serine protease: synthesis of radioactive and stable isotope‐labeled potent inhibitors

Drug candidates labeled with radioactive and stable isotopes are required for absorption, distribution, metabolism, and excretion (ADME) studies, pharmacokinetics, autoradiography, bioanalytical, and other research activities. The findings from these studies are crucial in the development of a drug candidate and its approval for human use. Herein, we report the synthesis of potent and selective hepatitis C virus serine protease inhibitors related to BILN 2061 and BI 201335 labeled with radioactive and stable isotopes. Synthetic efforts were focused on the common substituted thiazole moiety, which is easily accessible via a Hantzsch's reaction of α-bromoketones and mono-substituted thioureas. In the radioactive synthesis, commercially available carbon-14 thiourea was utilized to prepare mono-substituted thioureas, which upon condensation with α-bromoketones in isopropanol followed by ester hydrolysis gave the desired carbon-14-labeled protease inhibitors. The same strategy was used to prepare these inhibitors labeled with stable isotopes. Mono-substituted thioureas were obtained from commercially available deuterium-labeled intermediates and then condensed with α-bromoketones followed by ester hydrolysis to give the deuterium-labeled inhibitors.

ChemInform Abstract: Indium-Mediated Reaction in Aqueous Media. Synthesis of Phenacyl Sulfides by Reactions of α-Bromoketones with Sodium Alkyl Thiosulfates.

Phenacyl sulfides are synthesized in moderate to good yields via reaction of α-haloketones with sodium alkyl thiosulfates promoted by indium metal in aqueous media.

ChemInform Abstract: Diastereoselective Aldol Reaction of α-Bromo Ketones with Aliphatic Aldehydes by Using Titanium(II) Chloride and Copper.

Highly diastereoselective aldol reaction of α-bromo ketones with aliphatic aldehydes was successfully carried out by using titanium(II) chloride and copper in dichloromethane at low temperature. Similarly, Reformatsky-type reaction of α-bromo thioester with aliphatic aldehydes was promoted under mild conditions to afford β-hydroxy thioesters in good to moderate yields.

A cascade reaction sequence en route to 7-substituted 2-aminopyrrolo[1,2- a]pyrimidine-4,6-diones and the corresponding acrylic acid derivatives

Reaction of α-bromo ketones with 6-amino-2-methylpyrimidin-4(3 H)-one under basic conditions and in the presence of atmospheric oxygen affords novel 7-substituted 2-amino-pyrrolo[1,2- a]pyrimidine-4,6-diones that are readily hydrolyzed to afford the corresponding acrylic acid derivatives. The reaction sequence consists of an initial alkylation, followed by an unexpected condensation, elimination, and oxidation sequence to afford the products. This cascade reaction sequence represents a rapid and unprecedented route to the described small molecules.

An Efficient and Convenient Method for Synthesis of 1‐Substituted Imidazoles.

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Synthesis of 1,4-diketones: reaction of α-bromo ketones with tetrakis(dimethylamino)ethylene (TDAE)

1,4-Diketones were prepared by the reaction of α-bromo ketones with tetrakis(dimethylamino)ethylene (TDAE) in moderate to good yields. Similarly, α-bromo esters were reductively coupled using TDAE to give the 1,4-diesters in moderate yields.

An Efficient and Convenient Method for Synthesis of 1-Substituted Imidazoles

A convenient method for the synthesis 1-substituted imidazoles was developed by the reaction of α-bromoketone with lithium imidazolide. The reaction gave the desired products in improved yields without the formation of 1,3-disubstituted imidazolium salts. Treatment of bromoacetaldehyde ethylene acetal, 2-(bromomethyl)tetrahydro-2H-pyran, and N-(bromomethyl)phthalimide with lithium imidazolide also gave the corresponding 1-substituted imidazole in good to excellent yields. Direct reaction of α-bromoketone with imidazole as control experiment afforded undesired 1,3-disubstituted imidazolium salts with the desired mono-substituted products.

Indium-mediated Reaction in Aqueous Media. Synthesis of Phenacyl Sulfides by Reactions of α-Bromoketones with Sodium Alkyl Thiosulfates†

Phenacyl sulfides are synthesized in moderate to good yields via reaction of α-haloketones with sodium alkyl thiosulfates promoted by indium metal in aqueous media.

Organometallic Reaction in Aqueous Media. Synthesis of α-Selenoketones by Reactions of α-Bromoketones with Diselenides Promoted by Indium

Organometallic Reaction in Aqueous Media. Synthesis of α-Selenoketones by Reactions of α-Bromoketones with Diselenides Promoted by Indium

Synthesis of 4-imidazolin-2-ones

The reaction of α-bromoketones with CO(NH2)2 and AcONH4 in aqueous acetic acid gave substituted 4-imidazolin-2-ones.

α-Enone by the Reaction of Aldehyde and α-Bromoketone with Tri-n-Butylstibine

Abstract α-Enones were readily obtained from the reaction of α-bromoketone with aldehydes mediated by tri-n-butylstibine.

Stereoselective Syntheses of cis-Cyanooxiranes by Reaction of α-Bromoketones with Cyanide Ion Adsorbed onto Hemin-Copolymer

Sterically controlled addition reactions of cyanide to α-bromoketones by using CN-modified hemin-copolymer in nonaqueous system were carried out, and cis-cyano-oxiranes were obtained selectively.

Facile routes to boron enolates. Et 3B-mediated Reformatsky type reaction and three components coupling reaction of alkyl iodides, methyl vinyl ketone, and carbonyl compounds

Reaction of α-bromoketones with Ph 3SnH in the presence of Et 3B provides boron enolates which react with carbonyl compounds to give β-hydroxyketones in good yields. Et 3B-induced Reformatsky type reaction of α-iodoketones with an aldehyde or ketone proceeds without Ph 3SnH.

Formation of α-enaminoketones from α-azidoketones: An elimination of molecular nitrogen from α-azidoketones

α-Enaminoketones are readily accessible through reaction of α-bromoketones with sodium azide followed by an elimination of molecular nitrogen. The reaction is base catalyzed and proceeds under relatively mild conditions. An anionic mechanism is proposed.

The preparation of 1-aryl- and 1-heteroaryl-alkene-1,2-dithiolates

It is shown that alkaline hydrolysis of 2-(NN-dialkylamino)-1,3-dithiolium salts produces solutions of ene-1,2-dithiolate salts which are trapped by reaction with iodomethane. The dithiolium salts were prepared by reaction of α-bromoketones with sodium NN-dialkyldithiocarbamates, followed by sulphuric acid-catalysed dehydrative ring-closure of the resulting β-oxoalkyl NN-dialkyldithiocarbamates.

Alkyne formation in the reaction of α-bromo ketones with arylsulfonylhydrazines

Alkynes can be produced by treating some α-bromo ketones with arylsulfonylhydrazines. The reaction is acid-catalysed and mesitylsulfonylhydrazine was the most efficient hydrazine reagent examined. The mechanism of the reaction has not been elucidated although it is shown not to proceed via an α-bromo mesitylsulfonylhydrazone.

On the Mechanism of the Reactions of α-Bromoketones with Triphenylphosphine

<b>On the Mechanism of the Reactions of α-Bromoketones with Triphenylphosphine</b>