Search

A highly regioselective ortho-allylation using the ketoxime substituent as directing group is presented.

Tricyclic benzopyrans are medicinally important biologically active compounds. Synthesis of a series of tricyclic benzopyrans derivatives via N-Heterocyclic carbene (NHC) catalyzed annulation of enals to α-methylidenetetralones/chromanones is described. This reaction afforded the benzopyrans in high yield with aromatic as well as aliphatic enals.

Ionic liquids (ILs) have been used in numerous applications in chemistry. Wet ILs constitute a new class of solvents with their own new and interesting properties. The properties of ILs are significantly influenced by the addition of water and also affect reaction rates and selectivity. IL/water mixing makes it easy to control the properties of the solution and the formation of these ionic liquid mixtures increases synthetic flexibility. In this review, mixtures of IL/water solvent system promoted organic reactions have been described and the results are compared with other solvent systems. In many cases IL/water combinations were superior compared to conventional organic solvents and biphasic IL/organic co-solvent media with respect to catalytic performance as well as to catalyst separation and recycling.

A nucleophilic heterocyclic carbene-mediated intramolecular homoenolate reaction strategy for the efficient synthesis of cyclopentene-fused macrocycles is reported.

For example, knoevenagel condensation of indole-3-carbaldehyde with pyrazolone (II) provides coupling product (III) which shows antibacterial activity (MIC value 50 μg/ml).

New thiomorpholine derivative (Va) exhibits radical scavenging activity greater than the standard ascorbic acid.

A new class of (1,4-phenylene)bis(arylsufonylpyrazoles and isoxazoles) were synthesized by 1,3-dipolar cycloaddition of nitrile imines and nitrile oxides to the 1,4-bis((E)-2-(arylsulfonyl)vinyl)benzenes in the presence of chloramine-T. Compound 7f exhibited pronounced antimicrobial activity.

Green chemistry is playing an important role for synthesizing organic compounds, due to its eco-friendly nature and low cost. In green chemistry, metal nanoparticles exhibited some useful physical and chemical properties (catalytic activity). Due to its diverse properties, nanoparticles can be utilized as a catalyst in various organic reactions. Recent research has been directed towards the utilization of eco-friendly and bio-friendly plant materials in nanoparticles synthesis. In our present work, TiO 2 nanoparticles (TiO 2 NPs) were synthesized using Annona squamosa peel extract and their catalytic applications were studied on the 2,3-disubstituted dihydroquinazolin-4(1 H )-one synthesis. Synthesized compounds were confirmed using FT-IR, 1 H NMR, 13 C NMR and GC–MS analyses.

Compound (IIIb) is found to exhibit slightly higher antioxidant activity than the standard ascorbic acid.

New compound (IIIa) displays radical scavenging activity in all the three tested methods greater than the standard ascorbic acid, and compounds (Va) and (VIIIa) show activities equal to the standard ascorbic acid.

via Sm(III)-catalyzed cyclocondensation reactions of the corresponding heterocyclic sulfonylacetic acid ester (I) with 2-aminoethanol, 2-aminoethanethiol or ethylenediamine, respectively

A new class of sulfonamidomethane linked mono- and bis-heterocycles are synthesized and evaluated for their antimicrobial and cytotoxic activities.

A simple NHC-catalyst promotes the reaction of enals with dienones to give unexpected cyclopentene derivatives (III).

A variety of sulfonamidomethane linked 1,3,4-oxadiazoles and 1,3,4-thiadiazoles were prepared and tested for antioxidant activity. The methyl substituted arylsulfonylaminomethyl-1,3,4-oxadiazole 9b showed excellent antioxidant activity.

9 Title compounds of type (IX) are prepared and screened for their anti-oxidant activities.

A variety of new sulfonylmethylamido-linked azole derivatives (V) (9 examples) are synthesized and evaluated for their antimicrobial activities.

The reaction of ketene dithiolates in the presence of K2CO3 lead to bisthioalkylated products and thienothiophene derivatives depending on the strength of the base. The 1,5-diamino groups in thienothiophene compounds are subjected to heterocyclization under PTC conditions to get a variety of fused heterocycles.

A new class of pyrrolyl and pyrazolyl sulfonamides was prepared from styrene-ω-sulfonanilides by treatment with tosylmethyl isocyanide and diazomethane, respectively.

Comparable yields of (II) are obtained regardless whether the E/Z-mixtures of the substrates are used or pure isomers.

Novel highly functionalized mono- and bis-heterocycles (VI)—(XI) are synthesized and tested for their antioxidant properties.

A series of novel heterocycles, bisbenzoxazolyl/benzothiazolyl/benzimidazolyl pyrazoles/isoxazoles/pyrimidines were synthesized and evaluated for their antioxidant activity. The bisbenzoxazolylisoxazole 10 exhibited good antioxidant activity when compared with the standard ascorbic acid.

The entitled compounds (III) are formed using a multistep one-pot methodology exploiting either lanthanide catalysis or microwave irradiation in a single step with high yields.

A ruthenium-catalyzed oxidative coupling of substituted aromatic and heteroaromatic esters with alkenes in the presence of catalytic amounts of AgSbF6 and Cu(OAc)2 to provide highly substituted alkene derivatives in good to excellent yields under an open atmosphere is described.

A variety of tetrasubstituted thiophene, thieno-thiophene and tris-heterocyclic compounds are synthesized by intra- or intermolecular cyclocondensation reactions of gem-cyanoester ketene dithiolates (IV).

Title compounds such as (VI), (VIII), (IX), (X), (XII) and (XIII) are synthesized starting with cyclocondensation of hydrazide (I) and carboxylic acid (II).

The sulfonyl activated (E)-olefin (I) is used as synthon for novel pyrrole and pyrazole derivatives by 1,3-dipolar cycloaddition of tosylmethyl isocyanide (II) and diazomethane (IV), respectively.

The facile synthesis of 1,3,4-trisubstituted cyclopentenes via homoenolate annulation of enals with heterocycle substituted chalcones is described.

The title compounds (V), (VII) and (VIII) are obtained by 1,3-dipolar cycloaddition of TosMic or diazomethane to the respective cinnamamide derivatives (III).

Compounds (VIIa) and (VIIc) exhibit excellent antibacterial activity against Gram-positive bacteria and good activity against Gram-negative bacteria.

The compounds (IV), (V), and (VII) are synthesized by using facile, simple and well-versed synthetic methodologies.

An expedient synthesis of enantioenriched substituted (benzofuran-yl)-aryl and heteroaryl carbinols, is described. A key feature of this protocol is synthesis of functionally varied benzofuran scaffolds via a Rap–Stoermer reaction/catalytic asymmetric transfer hydrogenation (ATH) using substituted salicylaldehyde and α-haloaryl, heteroaryl ketones.

With a view to obtaining biologically interesting heterocycles, the new class of the heterocyclic compounds (IV), (V), (VII), (IX), and (XI) are prepared by using facile, simple and well established synthetic methods.

12 Aminosulfonyl-1,3,4-oxadiazoles and the corresponding 1,3,4-thiadiazoles of type (III), (IV), (VI), and (VII) are screened for their antimicrobial and antioxidant activities.

A new class of sulfone-linked bis(heterocycles) having two different heterocyclic rings is synthesized.

Exploiting lanthanide chemistry and 1,3-dipolar cycloaddition technology, title compounds (V) are prepared as a new class of substituted pyrroles.

Synthesis of several shape-specific hosts through heteroaromatic annulation on cis,syn,cis-triquinanedione 1 and X-ray crystal structure determination of one of them, 4a, is reported. Preliminary results of complexation between cleft 5a and diamines are reported.