A rapid synthesis of highly functionalized 2-pyridones and 2-aminopyridines via a microwave-assisted multicomponent reaction

International audienc

A rapid synthesis of highly functionalized 2-pyridones and 2-aminopyridines via a microwave-assisted multicomponent reaction

International audienc

Synthesis, characterization and activity in cyclohexene epoxidation of V2O5-TiO2 anatase xerogel

International audienceThe system of V2O5-TiO2 catalysts with V2O5 contents from 5 to 20 wt% were prepared by the sol-gel route and calcined at 500 A degrees C. The mixed oxide series presented the crystalline structure of TiO2 anatase phase. BET analysis showed a medium surface area decreasing from 73 to 19 m(2) g(-1) when V2O5 content rose from 5 to 20 wt%. The results of pyridine adsorption followed by FT-IR indicate that the catalysts display identical surface acid densities, independently of the V2O5 content, and both Bronsted and Lewis acid sites are present on their surfaces. The V2O5 system presents an activity and selectivity during the cyclohexene oxidation reaction. The presence of V2O5 increases the catalyst efficiency and leads to a selectivity change from cyclohexenol (blank test) to epoxide, with a maximum for 15 wt% V2O5. The conversion of cyclohexene was 46 % while the selectivity to epoxide was higher (75 %)

Polyethylene Glycol (PEG 300) and Water–Ethanol as Benign Solvent Systems for the Synthesis of a Novel Series of 2-Hydroxynaphthalen-1(4 H )-Ones

International audienc

Structure and absolute stereochemistry of the anticancer agent EBC-23 from the Australian rainforest

EBC-23 (2), a prostate anticancer agent, was isolated from the fruit of Cinnamomum laubatii (family Louraceae) in the Australian tropical rainforest. Extensive NOE experiments enabled the relative stereochemistry of the proposed EBC-23 (2) structure to be determined. Total synthesis of both enantiopodes over nine linear steps, involving challenging RCM and spiroacetal cyclizations, confirmed the gross structure and relative and absolute stereochemistry

Preparation of Polysubstituted Isochromanes by Addition of ortho-Lithiated Aryloxiranes to Enaminones

The reaction of ortho-lithiated aryloxiranes with various enaminones straightforwardly affords new functionalized isochromanes as mixtures of two epimeric stereoisomers in reasonable to very good yields (50–90%). The two diastereomers, which show a high structural variability, can be easily separated by column chromatography