Rhodium(III)-Catalyzed Synthesis of Spiropiperidine Derivatives via C-H Activation

Spiropiperidine derivatives, an important class of bioactive molecules, were synthesized under mild conditions by rhodium(III)-catalyzed intramolecular ArC-H activation. This reaction provides a novel route to highly substituted tricyclic spiropiperidines in good to excellent yields. Under acidic conditions the resulting enamines reacted with pendant amides to afford spiropiperidines derivatives possessing an original tetracyclic structure.