Relative Rates of Bromine-Magnesium Exchange Reactions in Substituted Bromobenzene Derivatives
The accessibility of functionalized Grignard reagents has opened new dimensions in organic synthesis. One of us has previously demonstrated that treatment of substituted bromoarenes with iPrMgCl·LiCl provides a straightforward access to functionalized aryl Grignard reagents by bromine–magnesium exchange. In accord with the suggested mechanism for these reactions, electron-acceptor groups have been observed to facilitate this conversion. We have now determined the relative rates of such exchange reactions to facilitate a targeted use of these reactions on polyfunctional compounds.