Anticancer activity and evaluation of apoptotic genes expression of 2-azetidinones containing anthraquinone moiety

Molecular Diversity - Nowadays, one of the principal causes of death in the world is cancer. A series of 2-azetidinones containing anthraquinone moiety with various substituents were synthesized...     

Synthesis of β-Lactams from Acids and Imines Using Thiocarbonyldiimidazole

Thiocarbonyldiimidazole has been found to be an efficient acid activator for the synthesis of β-lactams by ketene-imine cycloaddition at room temperature. The experimental procedure is simple and results in excellent yields of the products. All products were characterized by spectral data and elemental analyses.     

Efficient one-pot synthesis of 2-azetidinones from acetic acid derivatives and imines using methoxymethylene-N,N-dimethyliminium salt

A cheap, versatile and convenient method for synthesis of β-lactams using methoxymethylene-N,N-dimethyliminium salt as an acid activator in Staudinger reaction is reported. This method is used for the preparation of monocyclic, spirocyclic, N-alkyl and three-electron-withdrawing group β-lactams. The products are obtained in good to excellent yields.     

Homogenized Lorentz-Drude optical response in highly nanoporous conducting gold layers produced by de-alloying

Nanoporous gold films produced by de-alloying AuAl₂ with void densities between 45% and 65% retain high infra-red reflectance and good conductivity. They act optically like a homogeneous Lorentz-Drude metal with a unique plasma frequency and an inter-band transition energy unchanged from that of dense gold. The link between and ω_p in dense gold is found using a simplification of the Bergman expansion for permittivity valid at infra-red wavelengths. The carrier relaxation time of the “effective metal” becomes the actual relaxation time in the Au network and the complex refractive indices (n, k) found using normal incidence spectrophotometry and oblique incidence ellipsometry agree closely with each other. The single pole approximation for the ratio in the infra-red allows estimates of void content and the apparent shift in carrier effective mass. It is then possible to model with no adjustable parameters, the full UV-visible-NIR spectral response, giving excellent agreement with data. A range of films with these properties are presented.     

DMF-dimethyl sulfate as a new reagent for the synthesis of β-lactams

A number of 2-azetidinones were synthesized in good to excellent yields by a novel reaction between Schiff bases, substituted acetic acids and alkoxymethylene-N,N-dimethyliminium salts, the adduct formed from DMF and O-alkylating agents. The advantages of this new method are mild reaction conditions, low cost, avoiding the use of chlorinating agents and easy purification of the products. The best results were obtained when DMF and dimethyl sulfate were used at room temperature.     

Synthesis of N-unsubstituted β-lactams from N-alkoxyphenyl-β-lactams with cobalt(III) fluoride

Mild and efficient oxidative N-dearylation of N-alkoxyphenyl-β-lactams with cobalt(III) fluoride proceeded in good to excellent yields to afford the corresponding N-unsubstituted β-lactams. Optimization of the solvent, molar ratio of reagents, time, and temperature are described.     

A straightforward approach to 2-azetidinones from imines and carboxylic acids using dimethyl sulfoxide and acetic anhydride

The direct synthesis of 2-azetidinones from imines and carboxylic acids under mild conditions is developed. Dimethyl sulfoxide (DMSO) can be activated by acetic anhydride and the resulting active species is used for the in situ generation of ketenes from carboxylic acids. This method is cheap, simple, convenient, and efficient and the products are easily isolated.     

One-pot synthesis of 1,3,4-thiadiazoles using Vilsmeier reagent as a versatile cyclodehydration agent

A simple and efficient synthetic method for the one-pot synthesis of 1,3,4-thiadiazoles utilizing Vilsmeier reagent was developed. In this method carboxylic acids and hydrazine were converted to 1,3,4-thiadiazoles in the presence of Vilsmeier reagent and Lawesson's reagent. The influence of the thionation reagent, solvent, temperature and time, in this reaction was discussed. The developed methodology for 1,3,4-thiadiazole synthesis has the advantage of simplicity, ambient reaction conditions, easy purification and good to excellent yield of products.