نتایج جستجو برای: alkenes
تعداد نتایج: 5720 فیلتر نتایج به سال:
vo2+ and its complexes with ethylenediamine (en), acetylacetonate (acac), 2, 2’-bipyridine(bpy) ligands, immobilized within nanoreactors of al-mcm-41 designated as vo2+/al-mcm-41 or vol2/al-mcm-41, were prepared and characterized by x-ray powder diffraction (xrd), ft-ir, bet nitrogen adsorption-desorption and chemical analysis techniques. vo2+/al-mcm-41 and vol2/al-mcm-41 were found to catalyze...
چکیده ندارد.
The aldehyde-selective oxidation of alkenes bearing diverse oxygen groups in the allylic and homoallylic position was accomplished with a nitrite-modified Wacker oxidation. Readily available oxygenated alkenes were oxidized in up to 88% aldehyde yield and as high as 97% aldehyde selectivity. The aldehyde-selective oxidation enabled the rapid, enantioselective synthesis of an important pharmaceu...
Extracts of Mandragora autumnalis (mandrake) fruit have been analyzed by GC–MS. One-hundred and thirty-five compounds were identified in extracts obtained from the fruit after removal of the seeds – twentythree n-alkanes, one branched-chain alkane, two cyclohexanes, eight alkenes, two branched-chain alkenes, three alcohols, three aldehydes, six ketones, eight heterocyclic compounds, four thio c...
A highly enantioselective (up to 97.5% ee) and diastereoselective (95:5 dr trans/cis) Cu(I)-catalyzed cyclopropanation of alkenes using phenyliodonium ylide generated in situ from iodosobenzene and methyl nitroacetate is reported. The cyclopropanation took place with high enantioselectivity for a wide range of alkenes, and the reaction was performed at room temperature. 1-Nitrocyclopropyl ester...
A nickel-catalyzed intermolecular [2 + 2] cycloaddition of conjugated enynes with alkenes has been developed. A variety of electron-deficient alkenes as well as electronically neutral norbornene and 1-decene were applicable to this reaction. The use of conjugated enynes circumvented possible side rections, such as oligomerizations and cyclotrimerizations. The isolation of reaction intermediate ...
The asymmetric hydroaminocarbonylation of olefins represents a straightforward approach for the synthesis enantioenriched amides, but is hampered by necessity to employ CO gas, often at elevated pressures. We herein describe, as an alternative, enantioselective hydrocarbamoylation alkenes leveraging dual copper hydride and palladium catalysis enable use readily available carbamoyl chlorides pra...
Functionalized vinyl pinacol boronates suitable for Suzuki cross-coupling reactions are synthesized using ruthenium-catalyzed olefin cross-metathesis of 1-propenyl pinacol boronate and various alkenes, including functionalized and 1,1-disubstituted alkenes. The resultant boronate cross products are stereoselectively transformed into predominantly Z-vinyl bromides and E-vinyl iodides. The vinyl ...
N-Alkyl-N-chlorosulfonamides add to alkenes under copper(I) catalysis. In reactions of styrene derivatives with terminal double bonds the addition products were obtained in excellent yield and high regioselectivity. Lower yields are obtained in addition reactions to non-aromatic alkenes. The reaction most likely proceeds via a redox catalysis and amidyl radicals, a concerted mechanism has been ...
The addition of nucleophiles to electron-deficient alkenes represents one of the more general and commonly used strategies for the convergent assembly of more complex structures from simple precursors. In this review the addition of diverse protic and organometallic nucleophiles to electron-deficient alkenes followed by enantioselective protonation is summarized. Reactions are first categorized...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید