نتایج جستجو برای: bromides

تعداد نتایج: 13171  

Journal: :Chemical communications 2015
Fanny Frausto Zachary C Smith Terry E Haas Samuel W Thomas

Diphenylacetylene (tolan) derivatives with self-complementary aryl halides and halogen bond-accepting nitriles form 2D bricklayer packing motifs when halogen bonding occurs. When halogen bonding is absent, as occurred with fluorinated aryl bromides, the molecules adopt other packing motifs. These results suggest halogen bonding is potentially useful for producing rarely observed 2D bricklayer m...

Journal: :Molecules 2012
Attila Bokros Annamária Bánfi Zoltán Kupihár Zoltán Kele Tünde Zita Illyés János Szolomájer Lajos Kovács

Highly reactive glycosyl chlorides and bromides have been analysed by a routine mass spectrometric method using electrospray ionization and lithium salt adduct-forming agents in anhydrous acetonitrile solution, providing salient lithiated molecular ions [M+Li]⁺, [2M+Li]⁺ etc. The role of other adduct-forming salts has also been evaluated. The lithium salt method is useful for accurate mass dete...

2016
Y. Mori C. Jaccard J. Von Der Weid M. Aegerter

— The spin lattice relaxation, radiative and microwave excitation processes of the triplet self-trapped exciton hâve been studied in alkali chlorides and bromides by measuring the transient response of the X-ray excited luminescence to résonant puise microwave. The model is applied to magnetic circular polarization data. The symmetry of dominant exciton-phonon coupling are discussed.

2014
Stephen D. Ramgren Neil K. Garg

A simple method for the preparation of aryl methyl ketones is reported. The transformation involves the Pd-catalyzed coupling of an acyl anion equivalent, acetyltrimethylsilane, with aryl bromides to afford the corresponding acetylated arenes in synthetically useful yields. The methodology is tolerant of heterocycles and provides a new method for arene functionalization.

Journal: :Chemical communications 2013
Liena Qin Hajime Hirao Jianrong Steve Zhou

A regioselective Heck reaction of aliphatic olefins and aryl bromides is realized at internal carbons of olefins. Methanol solvent promoted halide ionization from neutral arylpalladium halide complexes via hydrogen bonding, so as to create cationic aryl-Pd species for regioselective olefin insertion.

Journal: :Chemical communications 2014
Takashi Kippo Ilhyong Ryu

A bromine-radical mediated three-component coupling reaction was effectively achieved by the use of allenes, electron-deficient alkenes, and allyl bromides and led to the synthesis of 2-bromo-1,7-dienes in good to high yields. This protocol was extended to the three-component process using alkylidenecyclopropane, which gave 2-bromo-1,8-diene along with alkylidenecyclopentane.

Journal: :Journal of the American Chemical Society 2005
Louis-Charles Campeau Sophie Rousseaux Keith Fagnou

Direct arylation reactions of pyridine N-oxides occur in excellent yield with complete selectivity for the 2-position with a wide range of aryl bromides. This reactivity permits the use of inexpensive, commercially available, and bench-stable pyridine N-oxides as replacements for problematic 2-metallapyridines in palladium-catalyzed cross-coupling reactions.

Journal: :Organic & biomolecular chemistry 2013
Adam R Ellwood Anne J Price Mortimer Jonathan M Goodman Michael J Porter

Thia-Claisen rearrangements have been carried out using N-benzylpyrrolidine-2-thione and chiral allylic bromides derived from D-mannitol. Introduction of a bromine atom onto the double bond of the allylic bromide reverses the sense of diastereoselectivity in the [3,3]-sigmatropic rearrangement. Density functional theory calculations lead us to rationalise the observed selectivity in terms of a ...

2017
Soneela Asghar Sanita B Tailor David Elorriaga Robin B Bedford

Readily accessed cobalt pre-catalysts with N-heterocyclic carbene ligands catalyze the Suzuki cross-coupling of aryl chlorides and bromides with alkyllithium-activated arylboronic pinacolate esters. Preliminary mechanistic studies indicate that the cobalt species is reduced to Co0 during the reaction.

Journal: :Tetrahedron letters 2010
Nolan T McDougal Jan Streuff Herschel Mukherjee Scott C Virgil Brian M Stoltz

Herein an efficient and direct copper-catalyzed coupling of oxazoline-containing aryl bromides with electron-deficient secondary phosphine oxides is reported. The resulting tertiary phosphine oxides can be reduced to prepare a range of PHOX ligands. The presented strategy is a useful alternative to known methods for constructing PHOX derivatives.

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