Pd-Catalyzed Enantioselective Dearomative Allylic Annulation to Access PPAPs Analogues.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) share a common bicyclo[3.3.1]alkenone core structure and attract numerous attention from synthetic organic chemists due to their fascinating biological properties and associated synthetic challenges. We present herein that Pd-phosphoramidite catalysts promote the enantioselective dearomative allylic annulation reaction between allyl desoxyhumulones and allylic dicarbonates, affording PPAPs analogues in good yields and enantioselectivities. The reaction likely proceeds through two-step dearomative allylation by Pd, and the C-allylation pathway is the dominant mechanistic model.