Search results for "Oxidative coupling"
showing 10 items of 52 documents
ChemInform Abstract: Rhodium Catalyzed Oxidative Coupling of Salicylaldehydes with Diazabicyclic Olefins: A One-Pot Strategy Involving Aldehyde C-H C…
2013
The title reaction involves the first example of ring opening and ring closing of bicyclic hydrazines (I) via metal catalyzed oxidative coupling reaction.
Modular Access to 9,9-Spirobifluorenes by Oxidative Coupling Using Molybdenum Pentachloride
2013
The strong oxidizing agent molybdenum pentachloride was used for an efficient direct C–C bond formation of 9,9-diarylfluorenes to the corresponding 9,9-spirobifluorenes. Thus, a versatile method that is compatible with labile groups, such as iodo moieties, was established. By this approach important building blocks for light emitting polymers were synthesized in high yields.
Gold Redox Catalytic Cycles for the Oxidative Coupling of Alkynes
2011
[EN] Au(I)/Au(III) catalytic cycles are catalytically competent to perform the oxidative coupling of alkynes in the homogeneous phase at room temperature and without any protecting atmosphere. Selectfluor as oxidant, wet acetonitrile as solvent, and sodium carbonate as base are the reagents of choice. Both aromatic and alkyl alkynes can be coupled, and mechanistic studies reveal that at least two gold species having different oxidation states are implicated in the key step of the coupling.
Iodine oxidative coupling of diene and triene-diolates of unsaturated carboxylic acids.
1991
Abstract Oxidative Coupling of the dianions of unsaturated carboxylic acids 1 , and 4 with iodine, which provides a convenient and facile preparation of γ,γ and e,e-dicarboxylic acids 2 and 5, apparently occurs through SET substitution of intermediate iodo-carboxylates.
ChemInform Abstract: Iodine Oxidative Coupling of Diene- and Triene-Diolates of Unsaturated Carboxylic Acids.
2010
Abstract Oxidative Coupling of the dianions of unsaturated carboxylic acids 1 , and 4 with iodine, which provides a convenient and facile preparation of γ,γ and e,e-dicarboxylic acids 2 and 5, apparently occurs through SET substitution of intermediate iodo-carboxylates.
ChemInform Abstract: Modular Access to 9,9-Spirobifluorenes by Oxidative Coupling Using Molybdenum Pentachloride.
2013
The reactions of diarylfluorenes and substrates (III) or (V) result in formation of spirobifluorenes and fluorene derivatives.
Rhodium catalyzed oxidative coupling of salicylaldehydes with diazabicyclic olefins: a one pot strategy involving aldehyde C–H cleavage and π-allyl c…
2013
An efficient one pot strategy for the synthesis of cyclopentene fused chromanone derivatives through the direct oxidative coupling of salicylaldehydes with bicyclic olefins in the presence of a rhodium-copper catalyst system is described. This is the first report on the ring opening-ring closing of bicyclic hydrazines via metal catalyzed oxidative coupling reaction.
Modular Approach to 9-Monosubstituted Fluorene Derivatives Using Mo(V) Reagents.
2016
Oxidative coupling using molybdenum(V) reagents provides fast access to highly functionalized 9-monosubstituted fluorenes. This synthetic approach is highly modular, is high yielding, and tolerates a variety of labile moieties, e.g. amides or iodo groups. The established protocol leads to promising precursors for pharmacologically important analogues of melatonin.
Electrochemical monitoring of the oxidative coupling of alkynes catalyzed by triphenylphosphine gold complexes
2012
Electrochemical monitoring of the oxidative coupling of alkynes in the homogeneous phase through catalytic cycles involving triphenylphosphine gold complexes and selectfluor as oxidant reveals that at least two gold species in +3 and +1 oxidation states are implicated. Electrochemically driven homocoupling of terminal alkynes using molecular oxygen as the oxidant can be performed using such catalysts. Keywords: Gold catalysis, Oxidative coupling of alkynes, Oxygen, Voltammetry
Increased conformational rigidity of humic substances by oxidative biomimetic catalysis
2005
A synthetic water-soluble meso-tetra(2,6-dichloro-3-sulfonatophenyl)porphyrinate of iron(III) chloride, Fe(TDCPPS)Cl, was employed as a biomimetic catalyst in the oxidative coupling of terrestrial humic materials. High-performance size-exclusion chromatography (HPSEC), solid-state nuclear magnetic resonance (CPMAS-(13)C NMR), electron paramagnetic resonance (EPR), and diffuse reflectance infrared spectroscopy (DRIFT) were used to follow conformational and structural changes brought about in different humic materials by the oxidative coupling. Increase in apparent weight-average molecular weight (Mw(a)) occurred invariably for all humic substances with the oxidative polymerization catalyzed …