Difluoropropargyl bromide

Starting from Difluoroallylic and Difluoropropargylic Derivatives Just like the esters of bromodifluoroacetic acids, difluoroallylic and difluoropropargylic bromides (via organometallic derivatives) can add onto aldehydes and couple with activated halides (Figure 2.17). ... 

Loh et al. reported that indium(O) mediated Barbier-type allylation was facilitated effectively in the presence of La(OTf)3 [24]. Lanthanide Lewis acid can be viewed as an ideal activator because Barbier-type reaction usually requires aqueous reaction media. With a wide variety of aldehydes, allylation of allyl bromide (5) proceeded to give y-adduct exclusively in good to excellent yield and diastereoselectivity under sonication (Table 13.10). Hammond et al utilized Barbier-type allylation for the synthesis of p,P-difluorohomopropargyl alcohols [25]. Eu(OTf)3 was found out to be the best catalyst to facilitate the reaction between difluoropropargyl bromide and aldehydes in aqueous THF under sonication (Table 13.11). With 5mol% of catalyst, the corresponding homopropargyl alcohols were obtained in moderate... 

Table 13.11 Barbier-type allylation of c i,a-difluoropropargyl bromide catalyzed by Eu(OTf)3 ...

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