The reported methodologies for the synthesis of chromane derivatives through the reaction of salicylaldehyde and enolates are discussed. The enolates and their equivalents involved in the reactions discussed in this article were derived from ketones, nitroalkanes, malononitrile and α,β-unsaturated compounds.

Xenobiotic reductase A (XenA) has broad catalytic activity and reduces various α,β-unsaturated and nitro compounds with moderate to excellent stereoselectivity. Single mutants C25G and C25V are able to reduce nitrobenzene, a non-active substrate for the wild type, to produce aniline. Total turnover is dominated by chemical rather than thermal instability.

The design and development of an extraordinarily interesting new class of chiral sulfur-olefin hybrid ligands with remarkable structural simplicity were described. These unique sulfinamide-olefin ligands have been proved to be highly effective ligands in rhodium-catalyzed asymmetric 1,4-addition reactions of aryl boronic acids to α,β-unsaturated carbonyl compounds (up to 99% yield and 98% ee).

A diamine-catalyzed asymmetric tandem reaction between α,β-unsaturated ketones and rhodanine derivatives has been developed to synthesize various spirocyclic compounds with high stereoselectivities (up to 99% ee and >20:1 dr). The products obtained contain two pharmaceutically relevant features: the biologically active rhodanine moiety embedded in a spirocyclic unit.

trifluoromethylated organic compounds, especially chiral quaternary alcohols bearing trifluoromethyl group are of important intermediates in drugs, agrochemicals and etc.an efficient epoxidation of β-cf3-β,β-disubstituted unsaturated ketones (6) has been developed with environmental benign hydrogen peroxide as the oxidant and f5-substituted chiral quaternary ammonium salt (1g or 5) derived from...

objectives: the objective of this research was to investigate the chemical composition and antibacterial activities of the fatty acids and essential oil from various parts of ligularia persica boiss (l. persica) growing wild in north of iran. materials and methods: essential oils were extracted by using clevenger-type apparatus. antibacterial activity was tested on two gram-positive and two gra...