Sarah E Wengryniuk, Andreas Weickgenannt, Christopher Reiher, Neil A Strotman, Ke Chen, Martin D Eastgate, Phil S Baran
Organic letters 2013 Feb 15A 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.
Sarah E Wengryniuk, Andreas Weickgenannt, Christopher Reiher, Neil A Strotman, Ke Chen, Martin D Eastgate, Phil S Baran. Regioselective bromination of fused heterocyclic N-oxides. Organic letters. 2013 Feb 15;15(4):792-5
PMID: 23350852
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