نتایج جستجو برای: heck reaction
تعداد نتایج: 413170 فیلتر نتایج به سال:
α-Halocarbonyl compounds undergo β-hydrogen elimination to give conjugated olefins in the presence of a transition-metal catalyst. However, a copper/triamine catalyst system can induce the alkylative Mizoroki–Heck reaction of styrenes with tertiary-alkyl halides possessing a withdrawing group under very mild conditions. This reaction provides an efficient synthetic methodology for tertiary-alky...
An environmentally friendly Matsuda-Heck reaction with arenediazonium tosylates has been developed for the first time. A range of alkenes was arylated in good to quantitative yields in water. The reaction is significantly accelerated when carried out under microwave heating. The arylation of haloalkylacrylates with diazonium salts has been implemented for the first time.
A variety of 2-hydroxy aldehydes on reaction with 3-butenoic acid afford in a one-pot reaction the corresponding 3-vinylcoumarins. As expected, extension of the delocalized π-electron system accomplished by Heck coupling reactions with aryl halides results in an increased fluorescence of the compounds whose applicability is yet to be established.
A stereocontrolled total synthesis of (+)-lysergic acid (1) is achieved using three metal-catalyzed methodologies for the construction of three key rings. Highlights of the synthesis include Pd-catalyzed indole synthesis to form the B ring, a RCM reaction to form the D ring, and an intramolecular Heck reaction to form the C ring.
Novel ionic water-soluble tetrabenzoporphyrins have been successfully synthesized via a cascade reaction based on the Heck reaction. The UV-Vis spectra of these porphyrins displayed red-shifted and broadened Soret bands, and significantly enhanced Q bands. These porphyrins are highly water soluble.
The palladium metal catalysed Heck reaction of 4-iodoanisole with styrene or methyl acrylate has been studied in a continuous plug flow reactor (PFR) using supercritical carbon dioxide (scCO2) as the solvent, with THF and methanol as modifiers. The catalyst was 2% palladium on silica and the base was diisopropylethylamine due to its solubility in the reaction solvent. No phosphine co-catalysts ...
The effect of substituents in the aniline donor and type heterocyclic acceptor/donor moieties on yields 1,2-trans- 1,1-isomer ethylene D-π-A chromophores Pd-catalyzed Heck reaction has been studied. Various – derivatives quinoline, quinoxaline, benzothiazole, carbazole indolizine were synthesized.
A modular total synthesis of the potent V-ATPase inhibitors archazolid A and B is reported. The convergent preparation was accomplished by late-stage diversification of joint intermediates. Key synthetic steps involve asymmetric boron-mediated aldol reactions, two consecutive Still-Gennari olefinations to set the characteristic (Z,Z)-diene system, a Brown crotyboration, and a diastereoselective...
A water-soluble and air-stable Pd(NH3)2Cl2/cationic 2,2'-bipyridyl system was found to be a highly-efficient and reusable catalyst for the coupling of aryl iodides and alkenes in neat water using Bu(3)N as a base. The reaction was conducted at 140 degrees C in a sealed tube in air with a catalyst loading as low as 0.0001 mol % for the coupling of activated aryl iodides with butyl and ethyl acry...
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