نتایج جستجو برای: imidazolium salts
تعداد نتایج: 29631 فیلتر نتایج به سال:
N-heterocyclic carbenes (NHCs), typically derived from imidazolium salts, have provided highly powerful ligands for catalysis. Recently, abnormal C4 bonding rather than normal C2 bonding has been discovered as a new carbene bonding mode. We were interested in comparing the consequences of these two bonding modes on the metal center. Therefore we synthesized related palladium complexes 1 and 2 c...
We describe the palladium-catalyzed multicomponent synthesis of 2-imidazolines. This reaction proceeds via the coupling of imines, acid chlorides and carbon monoxide to form imidazolinium carboxylates, followed by a decarboxylation. Decarboxylation in CHCl(3) is found to result in a mixture of imidazolinium and imidazolium salts. However, the addition of benzoic acid suppresses aromatization, a...
In the title compound, 2C6H11N2 (+)·P2Se8 (2-) or [EMIM]2P2Se8 (EMIM = 1-ethyl-3-methyl-imidazolium), the anions, located about inversion centers between EMIM cations, exhibit a cyclo-hexane-like chair conformation. The cations are found in columns along the a axis, with centroid-centroid distances of 3.8399 (3) and 4.7530 (2) Å. The observed P-Se distances and Se-P-Se angles agree with other s...
A diverse series of chiral bicyclic NHC/Ir complexes were prepared via a previously developed divergent synthesis of chiral imidazolium salts. Among the complexes, 8dz was found to be an excellent catalyst precursor for the Ir-catalyzed asymmetric transfer hydrogenation of ketones. The reaction of ketones with 8dz proceeded smoothly to give corresponding alcohols with high enantioselectivities ...
Graphene is a leading contender for the next-generation electronic devices. We report a method to produce graphene membranes in the solution phase using polymeric imidazolium salts as a transferring medium. Graphene membranes were reduced from graphene oxides by hydrazine in the presence of the polyelectrolyte which is found to be a stable and homogeneous dispersion for the resulting graphene i...
The Ge(IV) chlorometallate complexes, [EMIM]2 [GeCl6 ], [EDMIM]2 [GeCl6 ] and [PYRR]2 [GeCl6 ] (EMIM=1-ethyl-3-methylimidazolium; EDMIM=2,3-dimethyl-1-ethylimidazolium; PYRR=N-butyl-N-methylpyrrolidinium) have been synthesised and fully characterised; the first two also by single-crystal X-ray diffraction. The imidazolium chlorometallates exhibited significant CH⋅⋅⋅Cl hydrogen bonds, resulting...
Using three different approaches, racemic 1-(perfluoroalkyl)ethylamines were synthesized from perfluoroalkyl iodides or perfluoroalkanoic acids, and further transformed to the corresponding N,N'-disubstituted ethane-1,2-diimines and ethane-1,2-diamines as mixtures of diastereoisomers. Their cyclization afforded imidazolium or dihydroimidazolium salts, which led to silver or palladium complexes ...
Since Forbes and Davis reported the design of a class of phosphoniumand imidazolium ion-based ionic liquids (e.g. 1, Fig. 1A) equipped with a pendant acidic sulfonic acid moiety, interest in Brønsted acidic ionic liquids (BAILs) has gathered considerable pace. These materials afford the practitioner the flexibility of a system which combines strong acidity with the traditional advantages associ...
Eleven resorcinarene cavitands bearing either one, two or four (3-R-1-imidazolylium)-methyl substituents (R = (n)Bu, Ph, Mes, (i)Pr(2)C(6)H(3)) anchored at resorcinolic "ortho" positions have been synthesised from the appropriate bromomethylated precursor. Combining the imidazolium salts with palladium acetate and Cs(2)CO(3) gave active Suzuki-Miyaura cross coupling catalysts. The highest activ...
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