A dianionic Ireland-Claisen rearrangement of chiral, nonracemic α-methyl-β-hydroxy allylic esters has been developed that proceeds with high diastereoselectivity and provides products containing three contiguous stereogenic carbons, including a quaternary center. The potential utility of the rearrangement for complex molecule synthesis is also demonstrated.

A novel two-dimensional NMR pulse sequence, H2BC, for long-range correlation of 1H and 13C nuclei is presented. The experiment has several attractive features compared to the widely used HMBC experiment, for example, (a) typically strong enhancement of correlations over two bonds while suppressing those over more bonds, that is, resolving ambiguities in standard HMBC spectra and showing two-bon...

The title compound, C(18)H(24)I(2), has an adamantanoid structure with tetra-hedral cages having four C atoms lying on the same plane [(I-)C-C-C-C(-I) torsion angle = 0°]. The plane is extended by the two I atoms, each having a deviation of 1.0 (6) Å [C-C-C-I torsion angle = 178.9 (4)°]. The central C-C bond connecting the two quaternary carbons seems enlarged [1.593 (9) Å] in comparison to the...

Organocatalytic asymmetric Michael reactions of fluorinated nucleophiles with nitroolefins catalyzed by Cinchona alkaloid-derived thiourea catalysts generated the desired Michael products containing vicinal fluorinated quaternary and tertiary chiral centers with exceptional enantioselectivity.

The adsorption of phenolic compounds from olive oil wastewater by commercial activated carbon was studied as a function of adsorbent quantity and temperature. The sorption kinetics and the equilibrium isotherms were evaluated. Under optimum conditions (8 g of activated carbon per 100 mL), the maximum sorption capacity of activated carbon expressed as mg of caffeic acid equivalent per g of activ...

The chiral N-heterocyclic carbene-catalyzed [2+2+2] cycloaddition of ketenes and carbon disulfide was realized to give the cycloadduct of 1,3-oxathian-6-ones in good yields with excellent enantioselectivities.

Recent advances in electrophilic trifluoromethylation reactions of carbonyl compounds and their usual surrogates are highlighted with particular focus on copper-catalysed (or mediated) C-CF3 bond forming reactions. Ketones and aldehydes (notably via their enol ether and enamine derivatives) enable electrophilic trifluoromethylation at the α-carbon of the carbonyl compounds, whereas aldehyde N,N...

The removal efficiency of 22 selected trace organic contaminants by sequential application of granular activated carbon (GAC) and simultaneous application of powdered activated carbon (PAC) with membrane bioreactor (MBR) was compared in this study. Both sequential application of GAC following MBR treatment (MBR-GAC) and simultaneous application of PAC within MBR (PAC-MBR) achieved improved remo...

To determine the effects of irradiation on the chemical attributes of sausages, TBARS values, volatile compounds, gaseous compounds, and hydrocarbons of vacuum-packaged sausages were analyzed during 60 d of refrigerated storage. A sulfur-containing volatile (dimethyl disulfide), a gas (methane), and radiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane...