Allenic organometallic compounds

The reactions between the imines and the allenic organometallic compounds give the three allylamines with very high stereoselectivity, while the reaction with 9-but-2-enyl-9-BBN gives the analogous erythro allylamines stereoselectivity (Scheme 12.1) [10]. 

Halogenation of alkenyl organometallic compounds Addition of hydrogen halides to triple bonds Halogenation of alkynes or allenes Addition of alkyl halides to triple bonds Addition of acyl halides to triple bonds... 

In 1996, Malacria et al. [139] reported on cobalt-mediated reactions of the related allenynes. Heating the allenyne 222 in the presence of cpCo(CO)2 accompanied by a photochemical activation of this organometallic compound delivered the cross-conjugated trienes 223 (Scheme 15.71). The second triple bond present in the substrate did not participate in the reaction, underlining the higer reactivity of the allene unit. 

Orpen, G., Brammer, L., Allen, F. H., Kennard, 0., Watson, D. G., Taylor, R., Tables of bond lengths determined by X-ray and neutron diffraction. Part 2. Organometallic compounds and co-ordination complexes of the d- and / block metals. 

Indium-mediated allylation of trialkyl(difluoroacetyl)silane 70 in aqueous media gives homoallylic alcohol 71 exclusively (Scheme 60). Both water and THF are essential for the allylation reaction. It is worth noting that homoallylic alcohol 71 is formed exclusively under these reaction conditions. On the contrary, enol silyl ether 72 is a major product of the fluorinated acylsilanes reaction with other organometallic compounds than indium via a Brook rearrangement and defluorination. Indium-mediated allylsilylation of carbonyl compounds provides a facile route to 2-(hydroxyethyl)allylsilanes. The allene homologs are similarly prepared (Scheme 61).244,244a... 

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