Letters in Organic Chemistry - Volume 8, Issue 6, 2011

BF2 Chelated azadipyrromethene dyes fluoresce in the near infrared and have potential applications in photodynamic therapy. When irradiated above 600nm these aza-BODIPY compounds react with triplet O2 in the body to form a reactive singlet oxygen species which leads to cell death. A small library has been synthesized of these potential PDT agents via a four step process, with varying substituent's on the aromatic ring Read More

Some novel chromone- and chromanequinoline hybrids and their aza-analogs were synthesized from 2-chloro- 3-quinolinecarboxaldehydes as starting materials. The cyclization of 2-hydroxychalcones in the presence of AcONa yielded chroman-4-ones, while, in the typical AFO conditions, the 2-corresponding quinolyl-3-hydroxyflavonols were obtained. These approaches were extended to 2-aminochalcones, which delivere Read More

We have synthesized and evaluated a small set of dual action HIV-Protease inhibitors, consisting of a catalytic site reversible inhibitor conjugated with a dimerization peptidic inhibitor, linked via a suitable selective end-modified poly(ethylene glycol), in an effort to obtain a synergistic effect with improved biological behaviour and more powerful pharmacological features, such as water solubility, cell permeability and bioavailability.

[MPSIm]+CF3COO- ionic liquid is an efficient green catalyst for the one-pot, three-component Mannich-type reaction of aromatic aldehydes, aromatic amines and cyclohexanone. The reaction was completed within 5-60 min to give the corresponding β-amino ketones in 82-98% yield at room temperature. The catalyst can be recycled at least four times without significant decrease in activity.

A number of novel oxa-bridged and methylene oxa-bridged bicyclic isoxazolidines have been synthesized using intramolecular nitrone cycloaddition. The reductive cleavage of N-O bonds of the isoxazolidines to provide novel medium-ring heterocycles oxazocines and oxazonines is also described.

The reaction of 1-(prop-2-yn-1yl)pyrimidin-2(1H)-imin with various halobenzenes in the presence of a palladium catalyst leads to the production of 2-benzylsubstituted imidazo[1,2-a]pyrimidines.

The lithium bromide mediated condensation of 1-amino-2-heteroaryl substrates with ethyl cyanoformate, to obtain versatile alkylcarbamate protected benzoheteroazolones was studied. This unprecedented reaction could be used to furnish different azolones like 2-benzimidazolones, 2-benooxazolones and 2-amino-thiazoles in good yields.

During the course of our investigation in the field of thienopyridine based antithrombotic agents, we have identified and synthesized 4'-(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-ylmethyl)-biphenyl-2-carboxylic acid derivatives 5a-i, a thienopyridine derivative with good in vivo activity against thrombus formation. These findings prompted us to prepare new 4'-(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-ylmethyl)-biphenyl-2-carboxyl Read More

Phosphonation of β-nitro-alkene with triethyl phosphite was achieved under microwave irradiation using CH2Cl2 as the solvent in the absence of catalyst with moderate to high yields (up to 90%). This method of formation of carbonphosphor bonds is simple, mild, convenient and effective. Synchronously, a number of vinylphosphonates derivatives were synthesized and evaluated biologically preliminary.

A novel protocol for the synthesis of Ibutilide Fumarate (raceme) was achieved from 2-pyrrolidinone with an overall yield of 15%. The core structure was constructed in one step based on Friedel-Crafts acylation with an acyl chloride containing an amino hydrochloride.

MgI2 etherate-catalyzed three-component condensation of aldehydes, amines and allyltributylstannane under mild and neutral reaction conditions was developed and efficiently afforded the corresponding homoallylic amine derivatives in good to excellent yields.

In this article, a mild and efficient protocol for the tetrahydropyranylation and tetrahydrofuranylation of various aliphatic and benzylic alcohols and phenols into their corresponding THP and THF ethers (with 3,4-dihydro- 2H-pyran, DHP and 2,3-dihydrofuran, DHF) has been developed using a catalytic amount of anhydrous FePO4 at room temperature and relatively short reaction times in good to excellent yields.

GPC analysis of a steam exploded lignin from wheat straw showed Mw = 3605 and Mz = 21155 g/mol and a bimodal distribution with molecular weights in the range 100-10000 g/mol. On the contrary, FT-ICR-MS showed that fragments with a mass higher than 4534 Da cannot be obtained. Furthermore, FT-ICR MS showed that lignin is not a completely random polymer, but it showed some regularity with a difference of 44.0 Read More

The stem bark of Calophyllum inophyllum gave one new prenylated dipyranoxanthone inophinone (1), together with two other xanthones, inophyllin A (2) and caloxanthone B (3) and three common triterpenes, friedelin (4), stigmasterol (5) and betulinic acid (6). 1D and 2D NMR spectral data (1H, 13C, DEPT, COSY, HMBC & HMQC) were used to elucidate the structures of these compounds