Conditions In Excellent Yields Research Articles

Copper-Mediated Trifluoromethylation of Heteroaromatic Iodides

This work discloses a protocol for the trifluoromethylation of aromatic and hetero­aromatic iodides under mild reaction conditions in excellent yield. The trifluoromethyl group is transferred from readily available (S)-(trifluoromethyl)-diphenyl sulfonium salts, whereby elemental copper acts as the reducing agent.

Thermal solvent-free synthesis of novel pyrazolyl chalcones and pyrazolines as potential antimicrobial agents

A novel approach was adopted for the synthesis of series of new pyrazolyl chalcones (3a-c) by the reaction of 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde (1) with different 5-acetylbarbituric acid derivatives (2a-c) under thermal solvent-free condition. The chalcones were then converted to the corresponding pyrazolines (4a-c) under the same condition in excellent yields. All the synthesized compounds were characterized using elemental analysis and spectral data (IR, (1)H NMR, and mass spectrometry). The synthesized compounds were tested for their antimicrobial activity by disk diffusion assay with slight modifications against Gram-positive, Gram-negative strains of bacteria as well as fungal strains. The investigation of antimicrobial screening revealed that compounds (3a-4c) showed good antibacterial and antifungal activities, respectively. Among the screened compounds, 3b showed more potent inhibitory activity (MIC=12.5 μg/ml) nearly to that of standard antibiotics ciprofloxacin, griseofulvin and fluconazole.

An environmental friendly approach for the synthesis of highly substituted imidazoles using Brønsted acidic ionic liquid, N-methyl-2-pyrrolidonium hydrogen sulfate, as reusable catalyst

Brønsted acidic ionic liquid, N-methyl-2-pyrrolidonium hydrogen sulfate, has been used as an efficient and reusable catalyst for the one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles under thermal solvent-free conditions in excellent yields.

Nano Fe 3O 4 as magnetically recyclable catalyst for the synthesis of α-aminophosphonates in solvent-free conditions

The three component, one-pot synthesis of α-aminophosphonates has been achieved using super magnetic nano iron oxide at 50 °C under solvent-free conditions in excellent yields. The major advantages of the present method are high yields, short reaction times, magnetically recyclable catalyst, and solvent-free reaction conditions.

ChemInform Abstract: An Efficient Solid-Phase Method for the Preparation of Diaryl Carbazones.

Abstract The preparation of diaryl carbazones on solid-phase is reported for the first time. Using Fe(NO3)3.9H2O as oxidant, seven diaryl carbazones have been synthesized under mild conditions in excellent yields. The method is convenient and efficient.

Oxidative aromatization of Hantzsch 1,4-dihydropyridines by sodium chlorite

Hantzsch 1,4-dihydropyridines were converted to the corresponding pyridines efficiently by sodium chlorite under mild conditions in excellent yields.

Scandium(III) Triflate–Catalyzed Efficient Synthesis of Substituted 1-Pyridylimidazo-[1,5-a]-pyridines

An efficient synthesis of substituted 1-pyridylimidazo-[1,5-a]-pyridines has been accomplished using scandium(III) triflate as catalyst under mild conditions in excellent yields.

An Unusual N‐Boc Deprotection of Benzamides under Basic Conditions

AbstractFor the first time, an unusal cleavage of N‐tert‐butyloxycarbonyl (N‐Boc) protection from N‐Boc‐protected benzamide under basic conditions in excellent yields is reported. The deprotection involves the N‐Boc emigration from the benzamide to form 2‐O‐Boc group followed by O‐Boc deprotection on the phenyl ring.

Synthesis and Insect Antifeedant Activity of Plumbagin Derivatives with the Amino Acid Moiety

A series of plumbagin derivatives (4a-4k) containing an amino acid moiety were synthesized under mild esterification conditions in excellent yields (35%-80%) and screened for their antifeedant activities in tobacco caterpillar (Spodoptera litura) and castor semilooper (Achaea janata) using a no-choice laboratory bioassay. The parent compound plumbagin lacked significant activity, but the analogues were effective in reducing feeding by two insect species. The introduction of an N-acetyl-l-amino acid side chain to the Michael adduct of plumbagin at the third position of the quinone moiety significantly increased antifeedant activity. Several of the analogues were also toxic or caused developmental abnormalities following topical administration.

A mild and efficient chemoselective N-benzyloxycarbonylation of amines using TBAB as a catalyst under solvent-free conditions

We describe a mild and efficient method for the chemoselective N-benzyloxycarbonylation of amines by treatment of amines and aminoesters with benzyloxycarbonyl chloride (Cbz-Cl) in the presence of TBAB under solvent-free conditions in excellent yields. The method is general for the preparation of a wide variety of N-Cbz derivatives of aliphatic, aromatic amines, and aminoesters.

Ethyl lactate as a tunable solvent for the synthesis of aryl aldimines

Ethyl L-lactate can be tuned with a cosolvent to create polarity conditions ideal for synthesizing aryl aldimines that crystallize directly out of solution within minutes under ambient conditions in excellent yields and requiring no further purification.

L‐Proline Catalyzed Enamination of β‐Dicarbonyl Compounds under Solvent‐free Conditions

AbstractA simple, general and efficient method has been developed for synthesis of various β‐enamino ketones and esters by reacting β‐dicarbonyl compounds with amines using a catalytic amount of L‐proline at room temperature under solvent‐free conditions in excellent yields.

A Versatile and Convenient Preparation of Unsymmetrical Diaryl Disulfides

We have developed a convenient method for the synthesis of unsymmetrical diaryl disulfides under mild conditions in excellent yields. The described method is based on the straightforward preparation of 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-sulfenyl bromide from readily available 5,5-dimethyl-2-sulfanyl-2-thioxo-1,3,2-dioxaphosphorinane or bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl) disulfide. The unsymmetrical diaryl disulfides can be obtained from aromatic thiol derivatives bearing electron-withdrawing or electron-donating groups.

One-pot, three-component route to 2 H-indazolo[2,1- b]phthalazine-triones

2 H-Indazolo[2,1- b]phthalazine-1,6,11(13 H)-trione derivatives were synthesized in a simple and efficient method from the three-component condensation reaction of phthalhydrazide, dimedone, and aromatic aldehydes under solvent-free conditions in excellent yields and short reaction times.

A Highly Efficient Synthesis of 3H‐(Pyrrol‐1‐yl)indolin‐2‐ones Catalyzed by InCl3

AbstractA systemic and comprehensive study has been made on the formation of 3H‐(pyrrol‐1‐yl)indolin‐2‐ones synthesized from various isatin derivatives and 4‐hydroxyproline catalyzed by InCl3 under a refluxing condition in excellent yields (83%–99%) and purity.

Catalytic Ring Opening of α‐Epoxyketones Using DDQ in Methanol Solution at Room Temperature and under Reflux Conditions in Excellent Yields.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Catalytic Ring Opening of α-Epoxyketones Using DDQ in Methanol Solution at Room Temperature and under Reflux Conditions in Excellent Yields

Catalytic ring opening reactions of α-epoxyketones by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in methanol solution at r. t. and under reflux conditions resulted in the formation of α-hydroxy-β -methoxyketones through Cβ -O bond cleavage in excellent yields.Whereas the type and nature of the additional substituent affects the rate of ring opening, the effect of temperature has an extreme influence on the rate of reactions. Cyclic voltammetric studies of DDQ at 15 °C and 33 °C support the increased electron-acceptor ability of DDQ by the increasing of temperature.

2,6-Dicarboxypyridinum chlorochromate: an efficient oxidizing agent for the very fast oxidation of Hantzsch 1,4- dihydropyridines

Dicarboxypyridinum chlorochromate (2,6-DCPCC) was used as a highly effective oxidizing agent for the very fast oxidation of dihydropyridines to their corresponding pyridine derivatives under simple and relatively mild conditions in excellent yields.

Epoxidation of aromatic α,β-unsaturated ketones using PVP–H 2O 2 under mild and heterogeneous conditions

α,β-Unsaturated ketones (chalcones) react with PVP–H 2O 2 in aqueous sodium hydroxide and 1,4-dioxane as solvent at 40 °C to give the corresponding epoxides under mild and heterogeneous conditions in excellent yields.

A Mild and Efficient Chemoselective Protection of Primary Alcohols as Pivaloyl Esters Using La(NO3)3·6H2O as a Catalyst under Solvent-free Conditions

Abstract Primary alcohols are selectively and efficiently protected as their pivaloyl esters with pivaloyl chloride in the presence of catalytic amounts of La(NO3)3·6H2O at room temperature under solvent-free conditions in excellent yields.