Reaction Of Arylglyoxals Research Articles

Synthesis of 7-hydroxy-6,7-dihydro-indole and 6′,7′-dihydro-3,7′-biindole derivatives from domino reactions of arylglyoxals or methyl ketones with enamines

A series of interesting 7-hydroxy-2-aryl-6,7-dihydro-indol-4(5H)-ones 3 was successfully synthesized in moderate to good yields by the domino reactions of different arylglyoxals 1 with enamines 2 under catalyst-free conditions.

Взаємодія арилгліоксалей з тіосечовинами

Literature data about the reaction of arylglyoxals with thiourea has been discussed. It has been shown that no systematic studies in this issue had ever been carried out, furthermore some data is contradictory. The reaction of arylglyoxals with thiourea is reported to be a stepwise process that depends on at least two factors. It is reaction conditions such as temperature and solvent. Also the nature of glyoxal may have crucial influence on the structure of products. In this article has been provided the convincing evidence of formation three different kinds of heterocyclic systems upon reaction of p -substituted phenylglyoxals with N -methyl and N -phenylthiourea.

ChemInform Abstract: Regiospecific Strategies for the Synthesis of Novel Dihydropyrimidinones and Pyrimidopyridazines Catalyzed by Molybdate Sulfuric Acid.

Abstract The one-pot reactions of aryl glyoxals with acetylacetone and urea using molybdate sulfuric acid (5 mol %) lead to the novel functionalized 5-acetyl-4-(aryloyl)-3,4-dihydropyrimidinones, which readily undergo the Knorr condensation with hydrazines to produce new pyrimido[4,5- d ]pyridazines. The present strategies are in accordance with green chemistry principles through the use of a safe and recyclable catalyst under solvent-free conditions.

Na2S-mediated thionation: an efficient access to secondary and tertiary α-ketothioamides via Willgerodt–Kindler reaction of readily available arylglyoxals with amines

The task of this paper is to provide an efficient process for synthesis of secondary and tertiary α-ketothioamides via Willgerodt–Kindler reaction of readily available arylglyoxals with amines using Na2S as an effective catalyst. A plausible role for Na2S in the reaction of arylglyoxals with primary amines is proposed.

A Facile and Expeditious One-Pot Synthesis of α-Keto-1,3,4-oxadiazoles

An efficient and high-yielding protocol for the preparation of α-keto-1,3,4-oxadiazoles has been developed. Formation of α-keto-1,3,4-oxadiazoles involves the 2-iodoxybenzoic acid/tetraethylammonium bromide mediated oxidative cyclization of hydrazide-hydrazones generated in situ from the reaction of aryl glyoxal and hydrazides. This one-pot protocol is reasonably general for the preparation of α-keto-1,3,4-oxadiazoles under mild conditions in short reaction times.

An efficient and facile regioselective synthesis of new substituted (E)-1-(3-aryl-7,8-dihydrocinnoline-5(6H)-ylidene)hydrazines and (1E,2E)-1,2-bis(3-aryl-7,8-dihydrocinnoline-5(6H)-ylidene)hydrazines

A study concerning the new substituted cinnoline synthesis is described. The use of a one-pot three-component method allows a simple regioselective and efficient synthesis of cinnoline derivatives via reaction of arylglyoxals with 1,3-cyclohexanedione and dimedone in the presence of hydrazine hydrate.

One‐pot Synthesis of Benzamidonaphtho[2,1‐b]furans and Benzamidobenzo[b]furans as Novel Polycyclic Heteroaromatic Compounds

AbstractAn operationally simple, green and efficient procedure for one‐pot synthesis of novel polycyclic heteroaromatic compounds such as benzamidonaphtho[2,1‐b]furans and benzamidobenzo[b]furans has been developed from the reaction of arylglyoxals, benzamide, and phenols. The reactions were mediated with low amounts of yttrium nitrate hexahydrate as a suitable Lewis acid catalyst without using solvent.

ChemInform Abstract: Zirconium Catalyzed Chemoselective Synthesis of New Amido‐Substituted Benzo[b]furans via a One‐Pot Reaction.

AbstractThe one‐pot three‐component reaction of arylglyoxals (II), benzamide (III) and phenol derivatives (I) and (V) in the presence of a Zr‐catalyst affords chemoselectively benzofurans (IV) and (VI), resp., rather than alternative oxazole derivatives.

Regioselective synthesis of 3-arylpyrido[2,3-b]pyrazines by reaction of arylglyoxals with 2,3-diaminopyridine

The traditional methods for the synthesis of quinoxalines and pyridopyrazines generally require high reaction temperature, strong acidic media, and mostly long reaction time, moisture sencitivity as well as high cost, and toxicity of the reagents, therefore, a practical and more efficient alternative is still of interest for direct synthesis of pyrido[2,3-

Palladium‐catalyzed arylation of arylglyoxals with arylboronic acids

AbstractA palladium‐catalyzed coupling‐type reaction of arylglyoxals with arylboronic acids was achieved by use of trimesitylphosphine as the ligand and K2CO3 as base in toluene, providing symmetrical and unsymmetrical benzil derivatives with yields ranging from moderate to excellent. Of particular mention, the rigorous exclusion of air and moisture is not required in these transformations. Copyright © 2009 John Wiley & Sons, Ltd.

Enantioselective Carbonyl‐Ene Reactions of Arylglyoxals with a Chiral Palladium(II)‐BINAP Catalyst

AbstractThe palladium(II)‐BINAP‐catalyzed enantioselective carbonyl‐ene reactions between ten arylglyoxals and five alkenes were systematically investigated and demonstrated good to excellent enantioselectivities with high ee values of up to 93.8 %. The results showed that both arylglyoxals and alkenes exert evident effects on the enantioselectivity. Particularly, the ortho‐methyl substituents of the substrates could increase the enantioselectivity. The achieved excellent enantioselectivities may be due to the corresponding substrate matches well fitting the chiral space created by the chiral palladium(II)‐BINAP catalyst. The ortho‐methyl substituents may improve the fitting of the substrate match to the chiral space created by the chiral catalyst, hence the enantioselectivity is improved. When using dienes (1,4‐diisopropenylbenzene and 1,3‐diisopropenylbenzene) as substrates in this reaction, only one of the two carbon‐carbon double bonds participated into the reaction affording tetrafunctional organic compounds with moderate enantioselectivities of up to 83.8 % ee. The chiral Lewis acid palladium(II) catalyst incorporating (R)‐BINAP, which is a conformationally restricted chiral ligand, is very stable in ionic liquids and could be recycled 21 times with retention of the high enantioselectivity.

Reaction of Arylglyoxals with Electron‐Rich Benzenes and π‐Excessive Heterocycles. Facile Synthesis of Heteroaryl α‐Acyloins

The reaction of arylglyoxals and their hydrates with electron‐rich benzenes and π‐excessive heterocycles, if conducted in the absence of catalysts, affords α‐benzoins.

Reaction of Arylglyoxals with Electron‐Rich Benzenes and π‐Excessive Heterocycles. Facile Synthesis of Heteroaryl α‐Acyloins.

Abstract The reaction of arylglyoxals and their hydrates with electron‐rich benzenes and π‐excessive heterocycles, if conducted in the absence of catalysts, affords α‐benzoins.

Selective ring closure to substituted pyrido[1,2-b]-as-triazinium salt

Reaction of arylglyoxal with 1,2-diaminopyridinium salt 1 under acidic conditions afforded 2-aryl-pyrido[1,2-b]-as-triazinium salt 9 selectively, whereas cyclization of the same dioxo compound with 1-amino-2-iminopyridine 5 under neutral conditions - due to “umpolung” of the exo nitrogen atom - led exclusively to the 3-aryl isomer 8.

Reaction of arylglyoxals with 3-methyl-1-phenyl-5-Pyrazolone

Reaction of arylglyoxals with 3-methyl-1-phenyl-5-Pyrazolone