2-Nitropyrrole cross-coupling enables a second generation synthesis of the heronapyrrole antibiotic natural product family†
The heronapyrroles are a family of antibiotic natural products containing the rare 2-nitropyrrole motif. We report here a second generation total synthesis that circumvents problems of selective pyrrole nitration and alkene formation that limited the utility of previous approaches. Stille sp3–sp2 cross coupling of a novel 2-nitropyrrole fragment was developed to install the key C7,8 olefin with complete regiochemical control. An unusual Hunsdiecker-type decarboxylative halogenation was also identified, providing access to the complex vinyl stannane coupling partners required for formation of the natural product.