AI Article Synopsis
- A novel technique for selectively brominating C2 positions on fused azine N-oxides is introduced, using tosic anhydride to activate the reaction and tetra-n-butylammonium bromide as the bromide source.
- The method yields C2-brominated compounds at moderate to excellent levels, with strong regioselectivity in most cases.
- The approach could potentially be adapted for C2-chlorination using Ts(2)O/TBACl, and it can be integrated into a one-pot process that combines oxidation and bromination with specific oxidants.
Article Abstract
A mild method for the regioselective C2-bromination of fused azine N-oxides is presented, employing tosic anhydride as the activator and tetra-n-butylammonium bromide as the nucleophilic bromide source. The C2-brominated compounds are produced in moderate to excellent yields and with excellent regioselectivity in most cases. The potential extension of this method to other halogens, effecting C2-chlorination with Ts(2)O/TBACl is also presented. Finally, this method could be incorporated into a viable one-pot oxidation/bromination process, using methyltrioxorhenium/urea hydropgen peroxide as the oxidant.
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