نتایج جستجو برای: preparation of alcohols
تعداد نتایج: 21170995 فیلتر نتایج به سال:
A method for the continuous preparation of alcohols by hydroboration/oxidation of olefins using flow techniques is described. The process allows the isolation of up to 120 mmol h−1 of the desired alcohol in a very rapid manner with good functional group tolerance. The flow setup can be modified to perform a continuous extraction of the desired alcohol from the biphasic mixture produced by the r...
The asymmetric hydrogenation of prochiral unsaturated compounds, such as alkenes, ketones, and imines, is one of the most efficient and straightforward methods for the preparation of optically active compounds. This method uses dihydrogen and small amounts of chiral transition metal complexes and is now recognized as economical, operationally simple, and environmentally friendly. It is frequent...
Allylic alcohols can be used directly for the palladium(0)-catalyzed allylation of aryl- and alkenylboronic acids with a wide variety of functional groups. A triphenylphosphine-ligated palladium catalyst turns out to be most effective for the cross-coupling reaction and its low loading (less than 1 mol%) leads to formation of the coupling product in high yield. The Lewis acidity of the organobo...
Whole-cell biocatalysts offer a highly enantioselective, minimally polluting route to optically active alcohols. Currently, most of the whole-cell catalytic performance involves resting cells rather than growing cell biotransformation, which is one-step process that benefits from the simultaneous growth and biotransformation, eliminating the need for catalysts preparation. In this paper, asymme...
Halohydrin dehalogenases catalyse the conversion of vicinal halohydrins into their corresponding epoxides, while releasing halide ions. They can be found in several bacteria that use halogenated alcohols or compounds that are degraded via halohydrins as a carbon source for growth. Biochemical and structural studies have shown that halohydrin dehalogenases are evolutionarily and mechanistically ...
Reduction of aldehydes and ketones to the corresponding alcohols in the presence of sodium cyanoborohdride as reductive agent and Tonsil clay as catalyst under solvent free conditions was investigated. Tonsil (catalyst) decreased the reduction time of each aldehyde and ketone to proportional alcohols in comparison with their reduction in the absence of catalyst with high degree purity of alcoho...
Alumina supported molybdenum catalysts were prepared with an impregnation method. The activity of the catalyst in the ethanolysis of Kraft lignin to C6-C11 molecules, i.e. alcohols, esters, monophenols, benzyl alcohols and arenes, was tested in a batch reactor at 280 °C with initial 0 MPa nitrogen. The complete conversion of lignin to small molecular chemicals was achieved without the formation...
A head-space gas chromatographic technique for the analysis of volatile bacterial metabolites is described. Bacteroides fragilis, Clostridium perfringens, and Propionibacterium acnes, cultured in a glucose-containing peptone yeast extract medium, were studied. The head-space technique was compared with the injection of the complete liquid culture medium, and solvent extracts thereof, into the g...
Three dehydrogenases – (R)-alcohol dehydrogenase from L. kefir, (S)-aromatic alcohol dehydrogenase from T. sp. and (S)-alcohol dehydrogenase from T. brockii – were tested for the preparation of enantiopure hydroxyl metabolites of pentoxifylline (PTX), propentofylline (PPT) and denbufylline (DBF). These metabolites have an important pharmacological significance. The experimental conditions were ...
An efficient method is described for the mild and rapid tetrahydropyranylation of alcohols and phenols using a catalytic amount of N-chlorosaccharin (1 mol %) and 3, 4-dihydro-2H-pyran under solvent-free condition at room temperature. Benzylic alcohols and phenols containing electron withdrawing or donating groups in various positions of phenyl ring, cinamyl alcohol, primary, ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید