Letters in Organic Chemistry - Volume 10, Issue 2, 2013

A practical process for the preparation of anhydroalditols from commodity carbohydrates has been described. Reductive cleavage of the glycosidic linkage in perallylated carbohydrates with triethylsilane gave the protected anhydroalditols, which were then deallylated using a PdCl2-CuCl2-Activated Charcoal system. Valuable anhydroalditols, such as 1,5-anhydro-D-glucitol, 1,5-anhydro-D-mannitol, 2,5-anhydro-D-glucitol, 2, Read More

The conditions in catalysts and in reaction time for the reaction of protected α-D-glucosamine hydrochloride with different substituted benzaldehydes have been investigated in the presence of various inorganic and organic bases. Based on obtained results, the general procedure for the synthesis of Schiff's bases from tetra-O-acetyl-β-D-glucosamine hydrochloride and substituted benzaldehydes has been optimize Read More

The synthesis of N,N'-diacetyl-β-chitobiosyl N-glycooxazoline 2 was investigated. A routine method was used to prepare the N-benzyloxycarbonyl (Cbz) protected trichloroacetimidate donors 11 and 13. The synthesis was carried through using polystyrene as solid-phase support and o-nitrobenzyl ether tether as linker. The target compound 2 was efficiently obtained by iterative glycosylations, catalytic hydrogenation, ac Read More

Some new unfused tricyclic aromatic systems containing various heterocyclic cores were synthesized. These compounds were prepared in good yields via appropriate routes using 6-methyl-2-phenylquinoline-3-carbaldehyde as a key intermediate. The antibacterial activity of the prepared compounds was evaluated against: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia and Salmo Read More

In this paper, a novel secondary dialkylammonium salt with three stations (G1) was synthesized in 5 steps. 1H NMR was used to study the threading of G1 through the cavity of dibenzo-24-crown-8 (DB24C8) and benzo-21-crown-7 (B21C7). The complexation of G1 and two crown ethers was proved to be slow-exchange systems. This result lays the foundation on the integrative self-sorting organization of G1, DB24C8 and B21C7.

A new application of Mohr's salt (ammonium iron (II) sulfate hexahydrate) has been found in an organic reaction in which the Knoevenagel condensation, Michael addition, and intermolecular cyclization of 4-hydroxyxoumarin, malononitrile and aromatic aldehydes led to novel and known pyranocoumarins. Simple operation, use of readily accessible commercial starting materials, good to excellent yields and short reaction Read More

A convenient synthesis of sulfonic esters from thiols and disulfides has been described. In situ preparation of sulfonyl chlorides from thiols is accomplished by oxidation with Chloramin-T, tetra-butylammonium chloride (t-Bu4NCl) and water. The sulfonyl chlorides are then further allowed to react with phenol derivatives in the same reaction vessel. Also, a facile synthesis of bis(indolyl)methanes from alcohols using TCCA/KBr/ Read More

A convenient method was established for the synthesis of some new 6,7-dihydro-2-(methylthio)-5- aminopyrazolo[1,5-a]pyrimidine-3-carbonitriles 4 and -[1,2,4]triazolo[1,5-a]pyrimidin-5-amines 5 from β- cyanohydrazines 3 and suitable ketene dithioketals 2-[bis(methylthio)methylene]propanedinitrile 1 and dimethyl Ncyanocarbonimidodithioate 2, respectively in good yields. The structure of t Read More

A facile, green and versatile method for the Boc protection of amines has been developed by a treatment with (Boc)2O without any additive at room temperature. The method is general for the preparation of N-Boc derivatives of aliphatic (acyclic and cyclic), aromatic, and heteroaromatic amines; primary and secondary amines. The advantages of this method are green, simplicity, short reaction times and excellent yields.

The microwave-assisted synthesis of N-alkylbenzamides from benzoic acid and primary aliphatic amines has been developed under solvent-free conditions. The different solid catalysts have been investigated. The suggested synthesis is environmentally friendly and excellent yields (97 - 99 %) have been reached.

The investigation results of an efficient pathway for the synthesis of high-performance 1, 4-diketo-3, 6- diphenyl pyrrolo [3, 4-c] pyrroles pigments using diethyl succinate in ionic liquids ([BMIM][BF4], and [HMIM][BF4]) has been reported. Synthesis of 3, 6-Bis (4-chlorophenyl)-2, 5-dihydropyrrolo [3, 4-c] pyrrole-1, 4-dione using [BMIM][BF4] is more efficient (81% at 30°C) than conventional methods (70% at 105-110°C). 3, 6-Bis (4- Read More

A novel series of N-alkyl/aryl substituted phthalimide analogs containing 2-bromopyridyl functionality were synthesized applying optimized Buchwald-Hartwig amination conditions using palladium acetate, cesium carbonate, and ±BINAP in toluene at 110°C under argon atmosphere. The target heteroaryl phthalimide derivatives were obtained in moderate yield ranging from 40% to 51%. In the extra precision (XP) docking Read More

In this paper we introduced the formation of a novel type of capsules resulting from the self-association between oppositely charged complementary building blocks in H2O. The assembly is based on the interaction between tetraphosphonatcalix[4]arenes 1 and tetraammonium calix[4]arene 2 and 3. Evidence for the formation of the expected 1:1 assemblies is provided by ESI-MS. Isothermal titration calorimetry Read More

A simple, efficient and ecofriendly procedure for the synthesis of tetrahydrobenzo[b]pyran derivatives using triphenylphosphine as catalyst under aqueous conditions has been developed. This new method has some advantages like the easy experimental protocol, shorter reaction time, higher yields and is benign for the environment with using water as solvent.