Regioselective functionalization of gem-bis(trifluoromethylated) alkanols

1. Download high-res image (103KB)
2. Download full-size image

     

Synthesis,structure and magnetic properties of the dinuclear complex [1,3-C6H4{NC(Ph)N(SiMe3)}2]3Dy2 coordinated by ansa-bis(amidinate) ligands with a m-phenylene linker

1. Download high-res image (135KB)
2. Download full-size image

     

Efficient and stereoselective synthesis of (S)-α-propargylglycine derivatives from allenylboronic acid

1. Download : Download high-res image (46KB)
2. Download : Download full-size image

     

Self-condensation of 2-(ethoxalylmethyl)chromones into new derivatives of isotetronic acid

2-(Ethoxalylmethyl)chromones undergo dimerization to dichromonyl derivatives of isotetronic acid in 62–89% yields on refluxing with 2,3-diaminopyridine in ethanol for 1–2 h.     

Cystoseira algae (Fucaceae): update on their chemical entities and biological activities

Cystoseira (Sargassaceae) is a genus of marine brown algae composed of about 40 species, which is distributed along the Eastern Atlantic and Mediterranean coasts. The biological potential of the Cystoseira genus has been investigated and several activities have been reported. Chemically, this genus contains a wide variety of secondary metabolites, such as terpenoids, steroids, phlorotannins and phenolic compounds. Additionally, other chemical components as, for instance, carbohydrates, triacylglycerols/fatty acids, pigments as well as vitamins have been identified in the studied species. Some of the isolated compounds were associated with the reported pharmacological properties, as for example antioxidant, anti-inflammatory, cytotoxicity, anticancer, cholinesterase inhibition, anti-diabetic, activities but also antibacterial, antifungal and anti-parasitic activities. In this review, we provide a comprehensive overview of the compounds isolated and identified after 1995 from the different species of Cystoseira, compiling more than 200 compounds isolated, together with their therapeutic potential.     

Batch and in-flow kinetic resolution of racemic 1-(N-acylamino)alkylphosphonic and 1-(N-acylamino)alkylphosphinic acids and their esters using immobilized penicillin G acylase

The kinetic resolution of racemic 1-(N-acylamino)alkylphosphonic acids 3 (R³ = OH) and their dimethyl esters 1, as well as 1-(N-acylamino)alkylphosphinic acids 4 (R³ = H or Ph) using penicillin G acylase (PGA) immobilized on three types of mesoporous silicas in both a batch slurry system and in a continuous-flow reactor was studied. The initial hydrolytic deacylation rates in the presence of those catalysts were measured and the relationships between the substrate structure and the enzyme efficiency are discussed. The stereospecific hydrolysis of the N-acyl group of both racemic N-acylated phosphorus analogues of amino acids and their esters catalyzed by the immobilized PGA proved to be a highly effective method for the kinetic resolution of all the investigated compounds, with the stereochemical preference of PGA for (R)-substrates.     

Synthesis and photophysical studies of novel 2-[5-(4-diethylaminophenyl)thiophen-2-yl]quinazoline derivatives

1. Download high-res image (109KB)
2. Download full-size image

     

Self-condensation of N-substituted (4H-thieno[3,2-b]-pyrrol-5-yl)methanols into bis(thienopyrrolyl)methanes

1. Download high-res image (85KB)
2. Download full-size image

     

Studies on the effects of doping cesium metal(III) halides of the type Cs3MIII2X9 (MIII = Sb or Bi, X = Cl or Br)

A series of compounds, Cs₃M^III₂X₉ (M^III = Sb and Bi, X = Cl or Br) are doped with impurity ions (Ba²⁺, Ca²⁺, Sn²⁺, Pb²⁺, Mg²⁺, Fe²⁺, Tl³⁺, In³⁺, Se⁴⁺). Lattices doped with Sn(II), Pb(II) and Se(IV) are colored. Sn-119m Mössbauer data are consistent with the donation of Sn-5s electron density from tin(II) to a conduction band to give a pseudo-tin(IV) electronic environment.     

Synthesis of 3-(N-arylthiocarbamoyl)chromones from 2-hydroxyaryl amino enones and isothiocyanates

1. Download high-res image (103KB)
2. Download full-size image

     

Gasification of metal-containing coals and carbons via their reaction with carbon dioxide

1. Download high-res image (104KB)
2. Download full-size image

     

Synthesis of 4H-1,3-benzoxazin-4-ones from 2,2-diazidobenzofuran-3(2H)-ones

Benzoxazine derivatives are useful building blocks and display various biological activities. We serendipitously discovered and subsequently developed a new one pot method for the synthesis of 2-(dimethyl amino)/2-morpholino/2- (piperidin-1-yl)-4H-benzo[e][1,3]oxazin-4-ones from corresponding substituted 2,2-diazidobenzofuran 3(2H) - ones and N-formyl dimethyl amine (DMF)/N-formylmorpholine/N-formylpiperidine using m-CPBA at 100?°C in moderate to good yields. We also demonstrated the utility of 4H-benzoxazines for the synthesis of other medicinally important compounds such as 2-hydroxyphenyl substituted 1,2,4-triazoles, unsymmetrical 1,3,5-triazines, and 1,2,4-oxadiazoles.     

Paramagnetic Pd+ centers in the polymeric matrices of palladium(I) sorbates and 4-pentenate

1. Download high-res image (95KB)
2. Download full-size image

     

Tris(methyltrihydroborato)(tetrahydrofuran)ytterbium(III) complex: structure and volatility

1. Download : Download high-res image (71KB)
2. Download : Download full-size image

     

New sterically hindered bis-catechol,bis-o-quinone and its bis-triphenylantimony(v) bis-catecholate. 3,5-Di-tert-butyl-6-methoxymethylcatechol as alkylating agent

1. Download high-res image (94KB)
2. Download full-size image

     

New all-cis-tetra(p-tolyl)cyclotetrasiloxanetetraol and its functionalization

New all-cis-tetra(p-tolyl)cyclotetrasiloxanetetraol and its derivatives with Si(CH = CH₂)Me and Si(H)Me₂ groups have been prepared and characterized by IR and NMR spectroscopy, GPC, mass spectrometry, TGA and DSC. Molecular and crystalline structures of the tetraol and its derivative with four Si(CH = CH₂)Me groups have been determined by single-crystal X-ray diffraction.     

Synthesis of 1-(hydroxyaryl)furo[3,4-c]pyridines from 1-amino(alkoxy)furo[3,4-c]pyridines and (poly)phenols

1. Download high-res image (123KB)
2. Download full-size image

     

Synthesis,structures and magnetic properties of two iron(ii) tris(pyridyl)phosphine sulfide complexes

1. Download high-res image (108KB)
2. Download full-size image

     

Electrochemical and spectroelectrochemical properties of tetra-tert-butylphthalocyanine indium(III)

1. Download high-res image (109KB)
2. Download full-size image

     

Syntheses of chiral fused 4,5-diazafluorene–bis(nopinane) derivatives

1. Download : Download high-res image (122KB)
2. Download : Download full-size image