1- Bromopropene

T rimethylsilylethoxy-mcthyl)-2-(tri-n-butyl-stannyl)indole 3-Bromopropene, Pd,(dba)j, tri-(2-furyl)phosphine 93 [1]... 

I I ndol-1 -ylmagnesium bromide 3-Bromopropene, benzene, 70 10-14hat20X [4]... 

Unlike the acid-catalyzed ether cleavage reaction discussed in the previous section, which is general to all ethers, the Claisen rearrangement is specific to allyl aryl ethers, Ar—O—CH2CH = CH2. Treatment of a phenoxide ion with 3-bromopropene (allyl bromide) results in a Williamson ether synthesis and formation of an allyl aryl ether. Heating the allyl aryl ether to 200 to 250 °C then effects Claisen rearrangement, leading to an o-allylphenol. The net result is alkylation of the phenol in an ortho position. 

Similarly 2,3-dibromo- and 2-acetoxy-3-bromopropene react with carbonyl compounds without the need for an inert atmosphere62. 

Similar reactions were also carried out with 3-bromopropene, l-bromo-2-butene, 3-bromocy-clohcxcnc. and 3-bromocyclooctene in refluxing ethanol as solvent24 . Zinc-mediated Barbier reactions can be accomplished with high yields in a mixture of saturated aqueous NH4C1/THF (5 1), at room temperature or below using a 1.2 to 2-fold excess of the halide over the carbonyl compound25. 

The chromium reagent, prepared from 3-bromopropene, exhibits a good ability to discriminate between axial and equatorial attack in 4-fcrf-butylcyclohexanone1. 

Bromomethane, see Methyl bromide Bromopentane, see Amyl bromide Bromopropane, see Propyl bromide 3-Bromopropene, see Allyl bromide 3-Bromopyne, see Propargyl bromide ... 

Reaction of the chiral lithium enolate of meso-2,6-dimethylcyclohexanone (6), generated by deprotonation with (R)-l-phenylethylamine and (/ )-camphor/(R)-l-phenylethylaniine derived chiral lithium amides (Table 1, entries 17 and 64) with 3-bromopropene, leads to homoallyl ketones of opposite absolute configuration in acceptable yield with poor to modest enantiomeric excess14, which can be determined directly by H-NMR spectroscopy in the presence of tris [3-(heptafluorohydroxymethylene)-D-camphorato]europium(III) [Eu(hfc)3]. 

Iron-acyl enolates, such as 2, prepared by x-deprotonation of the corresponding acyl complexes with lithium amides or alkyllithiums, are nearly always generated as fs-enolates which suffer stereoselective alkylation while existing as the crmt-conformer which places the carbon monoxide oxygen anti to the enolate oxygen (see Section 1.1.1.3.4.1.). These enolates react readily with strong electrophiles, such as primary iodoalkanes, primary alkyl sulfonates, 3-bromopropenes, (bromomethyl)benzenes and 3-bromopropynes, a-halo ethers and a-halo carbonyl compounds (Houben-Weyl, Volume 13/9 a, p 413) (see Table 6 for examples). 

ALLYL BROMIDE Broinallylene, 3-bromopropene, 3-bromopropylene Flammable Liquid, I 3 3 1 ... 

Electronegative substituents within the coupling path decrease while those at the coupling carbon atoms increase 3JCH with cis and trans protons, as shown for 2- and 3-bromopropene [129]. 

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