Letters in Organic Chemistry - Volume 9, Issue 6, 2012

A convenient and simple method for synthesis of primary amines has been developed by direct amination of B- Chlorodialkylboranes. This general procedure has been applied to synthesize acyclic, cyclic, hindered and chiral amines in very high yields using both hydroxylamine-O-sulfonic acid and monochloroamine as reagents.

In this study analogues of compounds based on pyrano[2,3-d]pyrimidine were synthesized. 1,3-dimethyl-5- (thiomethyl)-2,4,7-trioxo-1,3,4,7-tetrahydro-2H-pyrano[2,3-d]pyrimidine-6-carboxylic acid 3 and 1,3-dimethyl-5- (thiomethyl)-2H-pyrano[2,3-d]pyrimidine-2,4,7(1H,3H)-trione 4 were obtained by the treatment of Triethylammonium 5- [(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)(thiomethyl)methyl]-1,3-dimethylpyrim Read More

The novel bifunctional compounds L1 and L2 carrying cluster glucosides as ligands for brain targeting liposomes were synthesized. 2-phenyl-1,3-dioxan-5-ol (8) and tetra-antennary alcohol (13) were used as the core scaffold to attach cholesterol derivatives by a triethylene glycol chain, while their remaining branches were linked with two or three benzylglucosides, which would be debenzvlated later to produce di-antennary gl Read More

Tetrabutyl ammonium fluoride (abbreviated as TBAF)-assisted palladium-catalyzed Suzuki reaction in neat water has been demonstrated under the ligand and base-free conditions. The cross-coupling of aryl or heteroaryl bromides with arylboronic acids generated the corresponding products in good to excellent yields in the presence of low concentration of palladium acetate in combination with TBAF under air.

A series of novel Schiff bases derived from dipicolinic acid was synthesized and evaluated for antioxidant and iron chelating activity. In most cases Schiff bases derived from di-hydrazide showed higher antioxidant activity than the ones derived from mono-hydrazide and some of them are very promising considering the fact of being better antioxidants than the standards used in the investigation. For iron chelating activity substit Read More

The regioselective nitroso Diels-Alder (NDA) reactions of trans 3-butadienyl-2-azetidinones with nitrosoarenes leading to the synthesis of novel and diastereomerically pure 3-(3,6-dihydro-2H-1, 2-oxazin-6-yl) azetidin-2-one derivatives and cis 3-butadienyl-2-azetidinones resulting in a diastereoselective mixture of regioisomers are investigated. The observed regioselective behavior is supported by computational model, Read More

An efficient one-pot synthesis of mono- and bis-6-alkoxy-2-amino-3,5-dicyanopyridines via a four or pseudoseven- component reaction of aldehyde, malononitrile and alcohol using K2CO3 as the base is described.

New nonracemic monemeric and dimeric quaternary ammonium salts have been synthesized by the reaction of commercially available quinine with phenanthrene derivatives and fully characterized by IR, NMR spectroscopy and Xray crystallographic analysis.

A facile and versatile procedure has been explored for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4Hchromenes, pyrano[2,3-d]pyrimidines and 1,4-dihydropyrano[2,3-c]pyrazole-5-yl cyanides. This protocol employs the one-pot three-component condensation of aromatic aldehydes and malononitrile with 5,5-dimethyl-cyclohexane-1,3- dione, 1,3-dimethyl barbituric acid or 3-methyl-1-phenyl-2-pyrazolin-5-ones respectivel Read More

A mild and efficient methodology for single pot ring opening of 3-aryl-4H-1,2-oxazines to γ-hydroxy ketones was developed using zinc and aqueous chelating ethers. The ether acts as ligand and co-solvent for the reaction. The ability of zinc ions to form stable complexes with chelating ethers activates the zinc towards reduction. Water is the proton source.

Turmeric contains three important analogs, curcumin, demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC), collectively called as curcuminoids. Curcumin, the most abundant of these curcuminoids is reported to have antioxidant, anti-inflammatory, neuroprotective, antimicrobial, nematocidal, antimutagenic, anticarcinogenic, antiretroviral and chemopreventive activities. Curcumin (a symmetric β dik Read More

An efficient solvent and catalyst-free synthesis of new Betti base derivatives via Mannich-type one-pot threecomponent condensation reaction of aminodiazines, salicylaldehyde and naphthols under solvent-free conditions is described. The reactions occur at 80 oC giving high to excellent yields of the products. The work-up procedure is very simple and the products do not require further purification with column chromatography.

One new xanthone, mesuaferrin C (1), was isolated from the root bark of Mesua ferrea. Two other known xanthones which are macluraxanthone (2) and caloxanthone C (3), along with three triterpenoids, β-sitosterol (4), friedelin (5) and betulinic acid (6) were isolated as well. The structures of these compounds were determined by 1D and 2D NMR and MS techniques.