Search results for "halogenation"
showing 10 items of 111 documents
Oxidative halogenation of substituted pyrroles with cu(II). Part II. Bromination of some ethyl 3-pyrrolecarboxylates and corresponding acids
1990
Ethyl 3-pyrrolecarboxylates and their corresponding acids are brominated with copper(II) bromide. The reaction afforded at 0°, with high-yield nuclear monobromination.
Preparation, reactivity and tautomeric preferences of novel (1H-quinolin-2-ylidene)propan-2-ones
2006
1,1-Difluoro-3-(1H-quinolin-2-ylidene)propan-2-one 1a, 1,1,1-trifluoro-3-(1H-quinolin-2-ylidene)propan-2-one 1b, 1,1,1-trifluoro-3-(4-chloro-1H-quinolin-2-ylidene)propan-2-one 1c and 1,3-dibromo-1,1-difluoro-3-(2-quinolyl)propan-2-one 2 are prepared and characterized by various spectroscopic techniques. The crystal structure of 1a is determined by X-ray diffraction. Furthermore, a series of previously known non-halogenated (1H-quinolin-2-ylidene)propan-2-ones 1d-1h are oxidized with AgBrO3 in the presence of AlCl3. In all cases, 2-(1-bromo-1-chloromethyl)quinoline 3 is obtained in high yield. The bromination order and sites of 1a are analyzed based on ab initio MP2 and DFT calculations for …
(3RS,1SR)-3-Bromo-3-(1-phenylpropyl)chroman-2,4-dione
2005
The title compound, C18H15BrO3, was obtained by bromination of phenprocoumone with N-bromosuccinimide. The X-ray structure confirms an earlier proposal concerning the regioselectivity of the reaction to introduce the Br atom at the 3-position.
Unexpected behaviour of copper(I) towards a tridentate Schiff base: Synthesis, structure and properties of new Cu(I)-Cu(II) and Cu(II) complexes
2001
cited By 17; International audience; The reaction of CuBr with 2,6-bis[1-(2,6-diisopropylphenylimino)ethyl]pyridine L afforded a new Cu(I)-Cu(II) derivative [CuBrL]2[Cu2Br4] (1), while the reaction of [Cu(CH3CN)4]PF6 with L in THF yielded the new Cu(I) compound CuL(THF)(CH3CN)PF6 (2). Derivative 2 further reacted with halogenated solvents to yield halogeno-Cu(II) salts, [CuClL]PF6 (3) using CHCl3 and [CuBrL]Br3 (4) using CHBr3. Compounds 1, 3 and 4 have been fully characterised by X-ray crystallography; they contain essentially similar [CuXL]+ cations with a square planar copper(II) co-ordination. However, the structure of compound 1 must be viewed as built of tetranuclear units since two […
A solvent-free regioselective iodination route of ortho-carboranes.
2006
Tetraiodo-ortho-carborane based X-ray contrast agents can be readily prepared in a high yield, fast, clean, regioselective fashion by a solvent-free reaction of ortho-carboranes with iodine in sealed tubes.
Ni@Fe2O3 heterodimers: controlled synthesis and magnetically recyclable catalytic application for dehalogenation reactions
2012
Ni@Fe2O3 heterodimer nanoparticles (NPs) were synthesized by thermal decomposition of organometallic reactants. After functionalization, these Ni@Fe2O3 heterodimers became water soluble. The pristine heterodimeric NPs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Mossbauer spectroscopy and magnetic susceptibility measurements. A special advantage of the heterodimers lies in the fact that nanodomains of different composition can be used as catalysts for the removal of environmentally hazardous halogenated pollutants.
Structure-activity relationship of dopaminergic halogenated 1-benzyl-tetrahydroisoquinoline derivatives
2009
Two series of halogenated 1-benzyl-7-chloro-6-hydroxy-tetrahydroisoquinolines were prepared to explore the influence of each series on the affinity for dopamine receptors. All the compounds displayed a high affinity for D(1)-like and/or D(2)-like dopamine receptors in striatal membranes, although they were unable to inhibit [(3)H]-dopamine uptake in striatal synaptosomes. The halogen placed on the benzylic ring in 1-benzyl-THIQs, compounds of the series 1, 2'-bromobenzyl derivatives with K(i) values into the nanomolar range, and the series 2, 2',4'-dichlorobenzyl-THIQ homologues, proves to be an important factor to modulate affinity at dopamine receptor. (C) 2009 Elsevier Masson SAS. All ri…
Chemoselective, Substrate-directed Fluorination of Functionalized Cyclopentane β-Amino Acids
2016
This work describes a substrate-directed fluorination of some highly functionalized cyclopentane derivatives. The cyclic products incorporating CH2 F or CHF2 moieties in their structure have been synthesized from diexo- or diendo-norbornene β-amino acids following a stereocontrolled strategy. The synthetic study was based on an oxidative transformation of the ring carbon-carbon double bond of the norbornene β-amino acids, followed by transformation of the resulted "all cis" and "trans" diformyl intermediates by fluorination with "chemodifferentiation".
(2-Pyridyl)sulfonyl Groups for ortho -Directing Palladium- Catalyzed Carbon-Halogen Bond Formation at Functionalized Arenes
2017
International audience; We describe an efficient palladium-catalyzed selective C-H ortho-monohalogenation (X=I, Br, Cl, F) of various functionalized (2-pyridyl) aryl-sulfones. ortho-, meta-and para-functionalization is tolerated at the arene group which undergoes C-H halogenation. Some modifications are also possible on the 2-(arylsulfonyl) heteroaryl directing groups. A comparison of the halogenation efficiency suggests that bromination is the practical method of choice, while chlorination and fluorination are possible but more challenging. Under forcing conditions ortho-dihalogenation can also be achieved.
1,2,6-Thiadiazine 1-Oxides: Unsaturated Three-Dimensional S,N-Heterocycles from Sulfonimidamides.
2020
Unprecedented three-dimensional 1,2,6-thiadiazine 1-oxides have been prepared by an aza-Michael-addition/cyclization/condensation reaction sequence starting from sulfonimidamides and propargyl ketones. The products have been further functionalized by standard cross-coupling reactions, selective bromination of the heterocyclic ring, and conversion into a β-hydroxy substituted derivative. A representative product was characterized by single-crystal X-ray structure analysis. peerReviewed