Reaction Of Aryl Methyl Ketones Research Articles

Iodine-Catalyzed Multicomponent Synthesis of Highly Fluorescent Pyrimidine-Linked Imidazopyridines.

Herein, we report a metal-free one-pot three-component reaction of aryl methyl ketones, 2-aminopyridines, and barbituric acids for the synthesis of pyrimidine-linked imidazopyridines using a catalytic amount of molecular iodine in DMSO medium. This process involves a one-pot C–H oxidation, followed by the formation of one C–C and two C–N bonds. A wide variety of aryl methyl ketones and 2-aminopyridines were found to be suitable for this methodology. The UV and fluorescence properties of the synthesized products were studied in water and DMSO media. Most of the synthesized products exhibited very good to excellent fluorescence quantum yield. Among all the products, compounds 4p and 4q showed the maximum fluorescence quantum yield (0.36) in water medium under basic conditions and compound 4c showed the maximum fluorescence quantum yield (0.75) in DMSO medium.

Merging Annulation with Ring Deconstruction: Synthesis of (E)-3-(2-Acyl-1H-benzo[d]imidazol-4-yl)acrylaldehyde Derivatives via I2/FeCl3-Promoted Dual C(sp3)-H Amination/C-N Bond Cleavage.

An unprecedented I2/FeCl3-promoted cascade reaction of aryl methyl ketones with 8-aminoquinolines for the convenient synthesis of (E)-3-(2-acyl-1H-benzo[d]imidazol-4-yl)acrylaldehydes was developed by merging annulation with ring deconstruction. This novel strategy unlocked the new reactivity of 8-aminoquinolines and provided an attractive platform for the ring opening of unactivated N-heteroaromatic compounds. Preliminary mechanistic investigation suggested that dual C(sp3)-H amination/C-N bond cleavage were key reaction steps. Furthermore, late-stage modification of the obtained products successfully delivered pyrazole and isoxazole derivatives, increasing the practicability and application potential of this methodology in organic synthesis.

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 green and practical one‐pot two‐step strategy for the synthesis of symmetric 3,6‐diarylpyridazines

A simple, mild, and efficient synthesis of symmetric 3,6‐diarylpyridazine derivatives using a green catalytic one‐pot two‐step reaction of aryl methyl ketones, arylglyoxal monohydrates, and hydrazine hydrate was developed. Environmentally benign nature, high atom‐economy, no harmful byproduct, easy workup procedure, no column chromatography steps, and moderate to excellent yields of the products are the salient features of this new multicomponent‐based methodology.

ONE-POT SYNTHESIS OF SOME NEW ?-BROMOKETALS AND ACETALS VIA 1, 8-DIAZABICYCLO [5.4.0] UNDEC-7-ENE-HYDROBROMIDE-PERBROMIDE

α-Bromoketals and acetals are important synthetic precursors in organic synthesis. In this work, some new α-bromoketals are synthesized by the reaction of aryl methyl ketones with diols in the presence of 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU) hydrobromide-perbromide in good isolated yields. The latter compound converts aldehydes to acetals and serves as a new and efficient reagent for the synthesis of acetals. Comparative studies of the preparation of α-bromoketal and acetals using some reported methods versus the present method show that DBUH-Br3 is one of the most efficient reagents for the preparation of these compounds. Conversion of carbonyl compounds to corresponding α-bromoketals and acetals in the presence of DBUH-Br3 under microwave irradiation is also described.

Asymmetric Mannich Reaction of Aryl Methyl Ketones with Cyclic Imines Benzo[e][1,2,3]oxathiazine 2,2-Dioxides Catalyzed by Cinchona Alkaloid-based Primary Amines.

Aryl ketones represent problematic substrates for asymmetric Mannich reactions due to a large steric hindrance exhibited by such compound species. A highly enantioselective direct Mannich reaction of aryl methyl ketones with cyclic imine benzo[e][1,2,3]oxathiazine 2,2-dioxides could be successfully carried out utilizing a combination of cinchona alkaloid-derived primary amines with trifluoroacetic acid (TFA); the primary amines feature a superior catalytic efficacy over secondary amines with a variety of sterically hindered carbonyl compounds as substrates. The reaction proceeded well with various cyclic imines in 89-97 % ee and with various aryl methyl ketones in 85-98 % ee. Moreover, the aryl carbonyl of a Mannich product could be transformed to ketoxime, which further undergoes a Beckmann rearrangement to produce an amide compound while maintaining enantioselectivity.

ChemInform Abstract: Tertiary Amino Thiourea‐Catalyzed Asymmetric Cross Aldol Reaction of Aryl Methyl Ketones with Aryl Trifluoromethyl Ketones.

Abstract An enantioselective aldol reaction of aryl methyl ketones with aryl trifluoromethyl ketones catalyzed by tertiary amino thiourea has been established. Under mild conditions, the corresponding β-trifluoromethyl-β-hydroxy ketone products were obtained with up to 89% ee.

Tertiary amino thiourea-catalyzed asymmetric cross aldol reaction of aryl methyl ketones with aryl trifluoromethyl ketones

An enantioselective aldol reaction of aryl methyl ketones with aryl trifluoromethyl ketones catalyzed by tertiary amino thiourea has been established. Under mild conditions, the corresponding β-trifluoromethyl-β-hydroxy ketone products were obtained with up to 89% ee.

ChemInform Abstract: One‐Pot Synthesis of α‐Ketoacetals from Aryl Methyl Ketones in the Presence of Selenous Acid Catalyzed by Boron Trifluoride Etherate.

AbstractThe reaction of aryl methyl ketones with triethylorthoformate proceeds under mild, solvent free conditions and tolerates a variety of functional groups.

Synthesis of Dimethyl Aryl Acylsulfonium Bromides from Aryl Methyl Ketones in a DMSO-HBr System

A new, simplified method for the synthesis of dimethyl aryl acylsulfonium salts has been developed. A series of dimethyl aryl acylsulfonium bromides were prepared by the reaction of aryl methyl ketones with hydrobromic acid and dimethylsulfoxide (DMSO). This sulfonium salt confirms that bromine production and the bromination reaction take place in the DMSO-HBr oxidation system. What’s more, it is also a key intermediate for the synthesis of arylglyoxals.

Triple condensation of aryl methyl ketones catalyzed by amine and trifluoroacetic acid: straightforward access to 1,3,5-triarylbenzenes under mild conditions

An efficient triple condensation reaction of aryl methyl ketones catalyzed by ethylenediamine and trifluoroacetic acid was reported. A broad scope of 1,3,5-triarylbenzenes was obtained in good to excellent yields. The reaction provides a novel and practical approach to access organic materials of polycyclic aromatic hydrocarbons under mild conditions.

Lack of correlation between catalytic efficiency and basicity of amines during the reaction of aryl methyl ketones with DMF-DMA: an unprecedented supramolecular domino catalysis

1-Methylimidazole exhibits an unusually high efficiency in promoting the reaction of aryl methyl ketones with DMF-DMA to form (2E)-1-aryl-3-dimethylamino-2-propenones which lacks correlation between the catalytic efficiency and the basicity of 1-methylimidazole in comparison to other amines. An unprecedented supramolecular domino catalysis rationalises the lack of correlation between the catalytic efficiency and basicity of the amines. The supramolecular assemblies have been characterized by mass-spectrometric ion fishing. The time-dependent increase/decrease in the concentration (ion current) of the supramolecular species consolidated the mechanism.

Silicotungstic acid catalysed Claisen Schmidt condensation reaction: an efficient protocol for synthesis of 1,3-diaryl-2-propenones

An efficient and clean synthesis of 1,3-diaryl-2-propenones has been carried out by Claisen Schmidt condensation reaction of aryl methyl ketones with a series of aromatic aldehydes at room temperature in the presence of the catalyst silicotungstic acid (STA). This method provides an ecofriendly, chemoselective, efficient and green synthesis of 1,3-diaryl-2-propenones in excellent yields.

ChemInform Abstract: The First Example of the Schmidt Reaction in Ionic Liquids.

The Schmidt reaction of aryl methyl ketones in ionic liquids (optimally in 1-ethyl-3-methylimidazolium triflate with CF 3 SO 3 H additive) proceeds at 40 °C within 10–30 h to give the corresponding acetanilides in good yields.

The first example of the Schmidt reaction in ionic liquids

The Schmidt reaction of aryl methyl ketones in ionic liquids (optimally in 1-ethyl-3-methylimidazolium triflate with CF3SO3H additive) proceeds at 40 °C within 10–30 h to give the corresponding acetanilides in good yields.

(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.

One-pot synthesis of 1,5-diketones catalyzed by barium isopropoxide

A tandem cross-coupling reaction of aryl methyl ketones with aromatic aldehydes has been accomplished employing barium isopropoxide as a catalyst, in which barium enolates are generated and then three consecutive reactions (aldol reaction/β-elimination/conjugate addition) occur; this one-pot procedure is a convenient method to obtain symmetrical 1,5-diketones in good yields. In some cases, addition of iso-propanol is effective in improving the chemical yield.

Ytterbium Triflate Promoted Tandem One-Pot Oxidation—Cannizzaro Reaction of Aryl Methyl Ketones.

For Abstract see ChemInform Abstract in Full Text.

Hypervalent Iodine(III) Mediated Synthesis of 2‐Substituted‐5‐Aryloxazoles

AbstractA direct and efficient method for the preparation of 2‐substituted‐5‐aryloxazoles was realized by reaction of aryl methyl ketones with various nitriles in the presence of phenyliodine(III) triflate.

ChemInform Abstract: Solvent-Free Three-Component Condensation Reaction of Aromatic Ketones with Aliphatic Amines and Formaldehyde.

A solvent-free procedure for the synthesis of several 1-aryl-2-(dialkylaminomethyl)-prop-2-en-1-ones 3 (a–e) and 4 (a–e) is reported. Reaction of arylmethyl ketones with formaldehyde and dialkylami...