I do lithiation of a aryl bromide having Phosphine group in the moiety . But even if I add little excess of of nBuLi then also 100% conversion is not happening . The nBuLi bottle is new. There is no LiOH ppt. What could be the problem ? I use ethyl acetate and liquid Nitrogen to maintain -78 degree throughout the reaction.
one simple way is deuteration of the intermediate. Just add D2O to quench the reaction mixture then see how much D was installed in to the newly formed arene.
I think you may check tlc or change the molar ratio of your reactants
Regards
Perhaps this reference will help:
Bromine–lithium exchange: An efficient tool in the modular construction of biaryl ligands. Bonnafoux, L.; Leroux, F. R.; Colobert, F.; Beilstein Journal of Organic Chemistry 2011, 7, 1278–1287 DOI:10.3762/bjoc.7.148
- Badges
- Science topic