نتایج جستجو برای: aryl
تعداد نتایج: 14792 فیلتر نتایج به سال:
We disclose an unprecedented transition-metal-free carbonylative cross coupling of aryl halides with potassium aryl trifluoroborates even at atmospheric pressure of carbon monoxide. This protocol is efficient, operationally simple, and shows wide scope with regard to both aryl halides and potassium aryl trifluoroborates containing a series of active functional groups.
Deprotonation with strong bases of N-vinyl ureas carrying an N'-aryl substituent leads to migration of the N'-aryl group from N to C via an allyllithium; with weaker bases and electron-deficient aryl rings the direction of the migration reverses, and aryl substituents α to the urea N atom may migrate from C to N.
Silica-grafted n-propyl-diaza-15-crown-5 (SGPDC) with immobilized palladium nanoparticles was found as an efficient heterogeneous catalytic system for the Heck and Suzuki coupling reactions and satisfied results were obtained. Different derivatives of aryl halides and alkenes under the Heck reaction were converted to the corresponding products with good efficiency. The presence of elec...
Two unique organometallic halide series (Ph3P)Au(4-Me-C6H4)(CF3)(X) and (Cy3P)Au(4-F-C6H4)(CF3)(X) (X = I, Br, Cl, F) have been synthesized. The PPh3-supported complexes can undergo both C(aryl)-X and C(aryl)-CF3 reductive elimination. Mechanistic studies of thermolysis at 122 °C reveal a dramatic reactivity and kinetic selectivity dependence on halide ligand. For X = I or F, zero-order kinetic...
Aryl-cobalamins are a new class of organometallic structural mimics vitamin B12 designed as potential ‘antivitamins B12’. Here, the first cationic aryl-cobinamides described, which were synthesized using newly developed diaryl-iodonium method. The obtained pairs coordination isomers, stereo-structure was unambiguously assigned based on homo- and heteronuclear NMR spectra. availability isomers w...
Selectively substituted o-teraryls are obtained by palladium/norbornene-catalyzed reaction of aryl iodides, aryl bromides and aryl boronic acids in ordered sequence; high selectivity is attained thanks to the addition of diethyl maleate acting as palladium ligand.
A general method for the Pd-catalyzed coupling of methanol with (hetero)aryl halides is described. The reactions proceed under mild conditions with a wide range of aryl and heteroaryl halides to give methyl aryl ethers in high yield.
A norbornene-mediated palladium-catalyzed sequence is described in which an alkyl-aryl bond and an aryl-heteroaryl bond are formed in one reaction vessel. The aryl-heteroaryl bond-forming step occurs via a direct arylation reaction. A number of six-, seven-, and eight-membered ring-annulated indoles, pyrroles, pyrazoles, and azaindoles were synthesized from the corresponding bromoalkyl azole an...
Abstract: Aryl halides and aryl triflates (triflate = trifluoromethanesulfonyl) are coupled with N-compounds to give the corresponding arylamines or arylhydrazines in the presence of a palladium catalyst, a suitable ligand, and a base. Catalyst systems consisting of palladium (II) and BINAP or triphenylphosphine are generally effective for the amination of a wide range of aryl halides and aryl ...
Mechanistic studies of the hydrogenolysis of aryl ethers by nickel were undertaken with (diphosphine)aryl methyl ethers. A Ni(0) complex containing Ni-arene interactions adjacent to the aryl-O bond was isolated. Heating led to aryl-O bond activation and generation of a nickel aryl methoxide complex. Formal β-H elimination from this species produced a nickel aryl hydride which can undergo reduct...
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