Conditions In Excellent Yields Research Articles

Sulfamic acid: an efficient, cost-effective and recyclable solid acid catalyst for the three-component synthesis of α-amino nitriles

α-Amino nitriles are synthesized by the three-component coupling reaction of aldehydes, amines and trimethylsilyl cyanide using sulfamic acid as a heterogeneous solid acid catalyst, under solvent-free conditions in excellent yields. The catalyst was recovered by simple filtration and was recycled in subsequent reactions.

Efficient Trimethylsilylation and Tetrahydropyranylation of Alcohols in the Presence of 1,3‐Dibromo‐5,5‐dimethylhydantoin.

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.

Erlenmeyer Synthesis for Azlactones Catalyzed by Ytterbium(III) Triflate under Solvent‐Free Conditions.

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.

Efficient Trimethylsilylation and Tetrahydropyranylation of Alcohols in the Presence of 1,3-Dibromo-5,5-dimethylhydantoin

Chemoselective trimethylsilylation and tetrahydropyranylation of benzylic and primary and secondary aliphatic alcohols proceed efficiently in the presence of 1,3-dibromo-5,5-dimethylhydantoin (DBH) under mild and completely heterogeneous reaction conditions in excellent yields.

Erlenmeyer Synthesis for Azlactones Catalyzed by Ytterbium(III) Triflate under Solvent‐Free Conditions

A series of 4‐arylidene‐2‐phenyl‐5(4)‐oxazolones were synthesized from cyclodehydration–condensation of hippuric acid, aromatic aldehydes, and acetic anhydride catalyzed by ytterbium(III) triflate under mild conditions in excellent yields.

Kröhnke pyridines: an efficient solvent-free synthesis of 2,4,6-triarylpyridines

A simple and efficient synthesis of 2,4,6-triarylpyridines is described from a novel reaction between chalcones and ammonium acetate under solvent-free conditions in excellent yields.

Silica Sulfate, an Efficient Catalyst for the Trimethylsilylation of Alcohols

An easy method for the preparation of trimethylsilyl ethers from alcohols and 1,1,1,3,3,3‐hexamethyl‐disilazane (HMDS) using silica sulfate as a catalyst under mild conditions in excellent yields is described.

Microwave-assisted efficient, one-pot, three-component synthesis of 3,5-disubstituted 1,2,4-oxadiazoles under solvent-free conditions

A novel synthesis of 1,2,4-oxadiazoles is described from a one-pot, three-component reaction between nitriles, hydroxylamine, and aldehydes under microwave irradiation and solvent-free conditions in excellent yields.

Sulphamic acid: An efficient, cost-effective and recyclable solid acid catalyst for three-component synthesis of homoallylic amines

Homoallylic amines are synthesized by the three-component coupling reaction of aldehydes, anilines and allyltributylstannane using heterogeneous solid acid catalyst, sulphamic acid under solvent-free conditions in excellent yields. The catalyst can be recovered by simple filtration and can be recycled in subsequent reactions. The method is simple, cost-effective and environmentally benign.

DABCO—POCl3, a Mild Dehydrating Agent for the Preparation of Nitriles from Aldoximes.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Aromatization of 1,4‐dihydropyridines in the presence of methanesulfonic acid/NaNO2/wet SiO2 under both heterogeneous and solvent free conditions

Abstractmagnified imageA combination of methanesulfonic acid and sodium nitrite in the presence of wet SiO2 was used as an effective oxidizing agent for the oxidation of 1,4‐dihydropyridines to the corresponding pyridine derivatives under mild and heterogeneous conditions in excellent yields.

DABCO–POCl3, a Mild Dehydrating Agent for the Preparation of Nitriles from Aldoximes

DABCO–POCl3 was found to be an efficient reagent for the dehydration of aldoximes to nitriles under mild reaction conditions in excellent yields.

Arylation of Nitromethane: Masked Nucleophilic Formylation of Fluoroquinolones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Molybdatophosphoric Acid/NaNO2/Wet SiO2 as an Efficient System for Oxidation of 1,4‐Dihydropyridines under Mild and Heterogeneous Conditions.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Scandium(III) Triflate as an Efficient and Reusable Catalyst for Synthesis of 1,5‐Benzodiazepine Derivatives.

Abstract 2,3-Dihydro-1 H -1,5-benzodiazepines have been synthesized in solvent-free conditions in excellent yield from o -phenylenediamines and ketones in the presence of a catalytic amount of Sc(OTf) 3 . This method is a very easy, rapid, and high yielding reaction for the synthesis of 1,5-benzodiazepine derivatives.

Natural HEU type zeolite catalyzed Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H) one derivatives

A new method for Biginelli reaction via heterogenous catalyst has been developed. This method uses natural Heulandite type zeolite (HTMA) as a catalyst for the one pot condensation of an aldehyde, urea and a 1,3-dicarbonyl compound under mild conditions in excellent yields.

Catalytic transesterification of ß-ketoesters with H-FER under solvent free conditions

Zeolite H-FER catalyzes the transesterification of β-ketoesters with variety of alcohols under solvent-less condition in excellent yields. The catalyst can be reused without any loss of activity.

Arylation of nitromethane: masked nucleophilic formylation of fluoroquinolones

Arylation of nitromethane with fluoroquinolones have been achieved through an S NAr reaction under mild conditions in excellent yield. Subsequently the nitromethyl derivatives obtained were readily transformed into the corresponding aryl aldehyde, overall as an equivalent process of nucleophilic formylation.

Scandium(III) triflate as an efficient and reusable catalyst for synthesis of 1,5-benzodiazepine derivatives

2,3-Dihydro-1 H-1,5-benzodiazepines have been synthesized in solvent-free conditions in excellent yield from o-phenylenediamines and ketones in the presence of a catalytic amount of Sc(OTf) 3. This method is a very easy, rapid, and high yielding reaction for the synthesis of 1,5-benzodiazepine derivatives.

An intriguing effect of lithium perchlorate dispersed on silica gel in the bromination of aromatic compounds by N-bromosuccinimide

A convenient and efficient procedure for electrophilic aromatic bromination has been developed by mixing of N-bromosuccinimide and an aromatic compound at room temperature on the surface of silica gel mixed with solid anhydrous LiClO4. All of the substrates examined underwent clean electrophilic aromatic bromination in reaction times of a few minutes to afford the corresponding bromoarenes under neutral conditions in excellent yield. In the case of thiophenol, no substitution reaction occurred, and the corresponding disulfide was obtained in excellent yield.Key words: LP-SiO2, NBS, arenes, electrophilic bromination, regioselectivity.