Propargylic organozinc compounds addition reactions

Allylic, benzylic and propargylic bromides will also react with zinc to give the corresponding organozinc bromides. Reaction with both C—C and C—N multiple bonds has already been shown to provide a potentially useful route to some Olefinic compounds [135]. However, the reaction with terminal acetylenes produces mixtures of mono- and bis-addition products (27) and (28) in low yields [136] (Scheme 57). 

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