Highly stereoselective synthesis of 2-Azabicyclo[3.1.0]hex-3-ene and 5-Azatricyclo[4.1.0.02,4]heptane scaffolds via Rh-catalyzed cyclopropanation of pyrrole

A rhodium-catalyzed cyclopropanation of pyrrole derivatives with electron-rich cyclopropenes is reported for the efficient access to vinyl functionalized cyclopropane fused pyrrolidine scaffolds, including 2-azabicyclo[3,1,0]hex-3-ene and 5-azatricyclo[4.1.0.02,4]heptane. The method features good yields and high diastereoselectivity. Electronic fine-tuning of these N-heterocycles via N-substituents proves key to the reactivity, offering a straightforward protocol for the synthesis of these cyclopropane-fused pyrrolidine scaffolds, which may have important medicinal relevance for further developments.