Palladium-Catalyzed Asymmetric Direct Intermolecular Allylation of α-Aryl Cyclic Vinylogous Esters: Divergent Synthesis of (+)-Oxomaritidine and (-)-Mesembrine

We demonstrate that alpha-aryl cyclic vinylogous esters are competent substrates in the direct intermolecular Pd-catalyzed asymmetric allylic alkylation, enabling a straightforward enantioselective synthesis of 6-allyl-6-aryl-3-ethoxycyclohex-2-en-1-ones, common motifs embedded in numerous structurally diverse natural products. As an initial demonstration of the utility of this protocol, the first catalytic enantioselective total synthesis of (+)-oxomaritidine and an improved five-step catalytic enantioselective synthesis of (-)-mesembrine have been completed divergently.

Automated summary

The study demonstrated that alpha-aryl cyclic vinylogous esters are effective substrates in the direct intermolecular Pd-catalyzed asymmetric allylic alkylation, allowing for the straightforward enantioselective synthesis of common motifs found in various natural products. As an initial application of this protocol, the first catalytic enantioselective total synthesis of (+)-oxomaritidine and an improved five-step catalytic enantioselective synthesis of (-)-mesembrine have been successfully completed in a divergent manner.