Pd-Catalyzed asymmetric decarboxylation for the construction of spiro[4.5]deca-6,9-dien-8-ones featuring vicinal quaternary carbons

A Pd-catalyzed decarboxylative strategy for the asymmetric construction of spiro[4.5]deca-6,9-dien-8-ones is reported. This approach utilizes modular vinyl methylene cyclic carbonates and p-quinone methides as reaction partners. The reaction could be performed at room temperature and generates CO₂ as the sole by-product. The corresponding products feature otherwise synthetically challenging vicinal quaternary carbons, which create great potential for complexity and diversity. The stereochemistry of the reactions is controlled with diastereo- and enantioselectivity being up to >20 : 1 dr and 96 : 4 er.