Allyl halides bromide

Allylation. Amalgamated Sm promotes reaction of allyl halides (bromide, iodide) with carbonyl compounds. Diallylation of esters occurs. ... 

IR bands due to both and p -CsHs groups were identified after the adsorption of allyl halides (bromide, iodide) on Cu(lOO) and Ag(l 11) surfaces. On Cu(lOO) there was evidence for both endo and exo p -CsHs units. " ... 

Acid chlorides and bromides, allyl halides, a-halo-ketones, esters, amides and nitriles react at 25° within 3 minutes. Vinyl and aryl halides are inert. 

Both resonance forms of the allylic carbocation from 1 3 cyclopentadiene are equivalent and so attack at either of the carbons that share the positive charge gives the same product 3 chlorocyclopentene This is not the case with 1 3 butadiene and so hydrogen halides add to 1 3 butadiene to give a mixture of two regioisomeric allylic halides For the case of electrophilic addition of hydrogen bromide at -80°C... 

Trichlorosilanc reacts with allyl halides under mildly basic conditions, subsequent treatment with methylmagnesium bromide giving rise to allyl(trimethyl)silanes15-16. 

To a suspension of 1.10 mmol of eopper(I) bromide-dimethyl sulfide in 2 mL of THF arc added 2.20 mmol of Bul.i in hexane at — 70 C und the clear solution is stirred at — 40°C for 40 min. 1.15 mmol of freshly fused zinc(Il) chloride dissolved in THF (1 M, 1.15mL) are added at - 70°C and after 15 min 1.0 mmol of the allylic halide in 1 mL of 1HF are added. After 15 h at -702C, the reaction mixture is diluted with hexane washed with sat. aq NaHC03 and sat. aq NaCI and then dried over MgS04. Tile solvent is removed, the product ratio analyzed by GC and the product is purified by chromatography. 

As complex 67 outperforms the Fe(0)-ate complexes in rate and yield, shown in the reaction of cyclooctenyl bromide with PhMgBr (full conversion complex 67 <20 min, 81% yield, 38 18 h, 39% yield), it was shown that both Fe(0)-ate and Fe (—2)-ate complexes should be intermediates in cross-coupling reactions, but the major contribution should be made by the route emanating from Fe(—2)-com-plexes. The superiority of Fe(—2)-ate complexes was also shown in the stoichiometric insertion of 67 into allylic halides, which proceeded much faster (<5 min) than with any higher valent iron complex (hours or days). 

The reductive coupling of allyl halides to 1,5-hexadiene at glassy C electrodes was catalyzed by tris(2, 2,-bipyridyl)cobalt(II) and tris(4,4 -dimethyl-2, 2/-bipyridyl)cobalt(II) in aqueous solutions of 0.1 M sodium dodecylsulfate (SDS) or 0.1 M cetyltrimethylammonium bromide (CTAB).48 An organocobalt(I) intermediate was observed by its separate voltammetric reduction peak in each system studied. This intermediate undergoes an internal redox reaction to form 1,5-hexadiene... 

There are few reports of oxidative addition to zerovalent transition metals under mild conditions three reports involving group 10 elements have appeared. Fischer and Burger reported the preparation of aTT -allylpalladium complex by the reaction of palladium sponge with allyl bromide(63). The Grignard-type addition of allyl halides to aldehydes has been carried out by reacting allylic halides with cobalt or nickel metal prepared by reduction of cobalt or nickel halides with manganese/iron alloy-thiourea(64). 

Alkyl Halides. Commonly, reductions with liquid silanes and liquid alkyl halides do not require the use of a solvent.186 When the alkyl halide is a solid, either pentane186 or dichloromethane may be used as solvent.192 No significant difference in reactivities is observed between alkyl chloride and bromide substrates,186 but allyl halides are more reactive than 2-halopropanes, which, in turn, are more reactive than 1-halopropanes.190,146... 

Alkynes react with haloethenes [38] to yield but-l-en-3-ynes (55-80%), when the reaction is catalysed by Cu(I) and Pd(0) in the presence of a quaternary ammonium salt. The formation of pent-l-en-4-ynes, obtained from the Cu(I)-catalysed reaction of equimolar amounts of alk-l-ynes and allyl halides, has greater applicability and versatility when conducted in the presence of a phase-transfer catalyst [39, 40] although, under strongly basic conditions, 5-arylpent-l-en-4-ynes isomerize. Symmetrical 1,3-diynes are produced by the catalysed dimerization of terminal alkynes in the presence of Pd(0) and a catalytic amount of allyl bromide [41]. No reaction occurs in the absence of the allyl bromide, and an increased amount of the bromide also significantly reduces the yield of the diyne with concomitant formation of an endiyene. The reaction probably involves the initial allylation of the ethnyl carbanion and subsequent displacement of the allyl group by a second ethynyl carbanion on the Pd(0) complex. 

Reduction of allyl bromides and iodides at vitreous carbon in an aptotic solvent generally gives good yields of the dimer. This product arises by rapid substitution by the allyl carbanion, formed in an overall two-electron reaction, onto a second molecule of allyl halide [55, 56]. 

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