نتایج جستجو برای: aryl vinyl ethers
تعداد نتایج: 32808 فیلتر نتایج به سال:
One of the most well-known, highly utilized reagents for ether cleavage is boron tribromide (BBr3), and this reagent is frequently employed in a 1:1 stoichiometric ratio with ethers. Density functional theory calculations predict a new mechanistic pathway involving charged intermediates for ether cleavage in aryl methyl ethers. Moreover, these calculations predict that one equivalent of BBr3 ca...
Nickel-catalyzed reductive cleavage of aryl alkyl ethers to arenes in absence of external reductant.
The reductive cleavage of the C-O bonds of aryl ethers has great potential in organic synthesis. Although several catalysts that can promote the reductive cleavage of aryl ethers have been reported, all such systems require the use of an external reductant, e.g., hydrosilane or hydrogen. Here, we report the development of a new nickel-based catalytic system that can cleave the C-O bonds of ethe...
Abstract A new type of ligand-free Ni-nanoparticles supported on rGO (size distribution average d = 9 ± 3 nm) was prepared and fully characterized via morphological (Fe-SEM), structural (P-XRD, HR-TEM), spectroscopic (ICP-EOS, XPS) analysis tools. The metal composite effectively employed in the unprecedented heterogeneously Ni-assisted cross-coupling reaction aryl/vinyl iodides thiocarboxylates...
The nucleophilicity of arenethiols can be augmented via hydrogen bonding with "naked" halide anion. The activity of the halide anions follow the order F(-) >> Cl(-) approximately Br(-) approximately I(-) and is dependent on the countercation (Bu(4)N approximately Cs approximately K > Na >> Li). The solvent plays an important role in nucleophilic activation as well as regeneration of the effecti...
The C?H olefination of substituted anisole derivatives by a Pd/S,O-ligand catalyst is reported. reaction proceeds under mild conditions with broad range aryl ethers bearing both electron donating and withdrawing substituents at ortho, meta para positions. Aryl are used as limiting reagents good yields site selectivities observed. methodology operationally simple can be performed aerobic conditi...
following our previous investigations on certain new aminoalkyl aryl ethers, which showed promising and outstanding local anaesthetic properties, the local anaesthetic activity and duration of action of a further selection of four novel derivatives of the above-mentioned series, used as hydrochloride salts, have been determined by the ill vivo rat sciatic nerve test. these are: n,n-dimethyl-2-(...
ABSTRACT Ru-catalyzed synthesis of mixed alkyl-alkyl acetals via addition of primary alcohols to allyl ethers has been extended to include long-chain and/or functionalized substrates. The catalytic systems for these reactions were generated from RuCl2(PPh3)3 and [RuCl2(1,5-COD)]x and phosphines [PPh3 or P(p-chlorophenyl)3] or SbPh3. Of particular importance is the almost quantitative eliminatio...
Diaryliodonium salts are demonstrated as efficient arylating agents of aliphatic alcohols under metal-free conditions. The reaction proceeds at room temperature within 90 min to give alkyl aryl ethers in good to excellent yields. Aryl groups with electron-withdrawing substituents are transferred most efficiently, and unsymmetric iodonium salts give chemoselective arylations. The methodology has...
An efficient K3PO4-mediated synthesis of unsymmetrical diaryl ethers using the ionic liquid [Bmim]BF4 (1-butyl-3-methylimidazolium tetrafluoroborate) as solvent has been developed. The procedure involves consecutive deprotection of aryl methane-sulfonates and a nucleophilic aromatic substitution (S(N)Ar) with activated aryl halides.
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