نتایج جستجو برای: acetates salts
تعداد نتایج: 28651 فیلتر نتایج به سال:
[reaction: see text] Monodentate phosphoramidites, in particular PipPhos and its octahydro analogue, are excellent ligands for the rhodium-catalyzed asymmetric hydrogenation of aromatic enol acetates, enol carbamates, and 2-dienol carbamates up to 98% ee. These latter substrates were hydrogenated selectively to the carbamates of the allyl alcohol.
Highly crystalline metal oxide nanoparticles such as CoO, ZnO, Fe(3)O(4), MnO, Mn(3)O(4), and BaTiO(3) were synthesized in just a few minutes by reacting metal alkoxides, acetates or acetylacetonates with benzyl alcohol under microwave heating.
A Cu-catalyzed [3+2]-type condensation reaction of oxime acetates and dialkyl acetylenedicarboxylates that provides highly substituted pyrroles under aerobic conditions is described. The newly formed pyrroles are easily employed for further transformations to prepare pyrrolo[2,1-a]isoquinoline skeletons.
We report the Cu-promoted oxidative cross-coupling of αfluoromalonate half-esters and aryl boron reagents to deliver monofluoro α-aryl acetates under mild conditions (in air at room temperature). The reaction uses a simple, readily available monofluorinated building block to generate arylated compounds with functional groups that are not easily tolerated by existing methods, such as aryl bromid...
Biosynthetic studies with (13)C-labelled acetates and methionine revealed that the infamous, food-related toxin bongkrekic acid from Burkholderia gladioli is a polyketide with acetate-derived beta-branches and a carboxylate terminus derived from the methyl group of an acetate.
Palladium-catalyzed cross-coupling reactions of organogold(I) phosphanes with allylic electrophiles.
Aryl and alkenylgold(I) phosphanes react regioselectively with allylic electrophiles such as cinnamyl and geranyl halides (bromide, chloride and acetates) under palladium catalysis in THF at 80 °C to afford the α-substitution product with moderate to high yields. When the reaction is performed with a chiral enantiopure secondary acetate, the α-substituted cross-coupling product is obtained with...
An NHC-catalyzed Michael/Michael/esterification domino reaction via homoenolate/enolate intermediates for the asymmetric synthesis of tetrasubstituted cyclopentanes bearing four contiguous stereocenters is described. A variety of α,β-unsaturated aldehydes and 2-nitroallylic acetates react well with good domino yields and high stereoselectivities.
Background Pluchea quitoc DC. (Asteraceae), a medicinal plant known as "quitoco," "caculucage," "tabacarana" and "madre-cravo," is indicated for inflammatory conditions such as bronchitis, arthritis, and inflammation in the uterus and digestive system. Objective This study evaluated the analgesic and anti-inflammatory activities of the triterpenes compounds obtained from P. quitoc aerial part...
A panel of lipases was screened for the selective acetylation and alcoholysis of silychristin and silychristin peracetate, respectively. Acetylation at primary alcoholic group (C-22) of silychristin was accomplished by lipase PS (Pseudomonas cepacia) immobilized on diatomite using vinyl acetate as an acetyl donor, whereas selective deacetylation of 22-O-acetyl silychristin was accomplished by N...
Six components of sporaviridin (SVD) were successfully isolated by HPLC using methano-1 M ammonium chloride as the mobile phase. Each component possesses expectedly antimicrobial activity. To ensure the structural relationship between the intact SVD and N-acetylated sporaviridins (N-Ac-SVD), they were converted to the corresponding of N-acetates by acetylation in methanol, whose structures had ...
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