Zinc Bromide / Lithium Bromide, typ. 25 % solution in Dibutyl Ether
The use of a 'ready-made' dibutyl ether solution avoids the handling of the very hygroscopic and dusty ZnBr₂ and LiBr powder.
The ZnBr₂/LiBr dibutyl ether solution was developed mainly for the application in organic synthesis, e.g.:
- transmetallation of organomagnesium and organolithium compounds to the corresponding zinc reagents for C-C coupling reactions (Negishi protocol)
- formation of zinc enolates by deprotonation of carbonyl compounds using standard bases followed by transmetallation with ZnBr₂
- catalysis of cycloaddition reactions e.g. Diels-Alder reactions of electron rich dienes with carbonyl compounds
- preparation of selective reducing agents, e.g. Zn(BH₄)₂ by reaction ofNaBH₄ with ZnBr₂
McGarvey, G.J. in Encyclopedia of Reagents for Organic Synthesis, Paquette, L.A., Ed. John Wiley and Sons, New York (1995), Vol. 8, 5544