Diversity-generation from an allenoate–enone coupling: syntheses of azepines and pyrimidones from common precursors

Amine-catalyzed coupling reactions of allenoate esters and α,β-unsaturated carbonyls lead to a diverse range of α,α′-disubstituted allenoates. With appropriately substituted monomers, intermolecular reactions can lead to pyrimidone products. Alternatively, with amine substituted allenoates, a 7-endo-dig cyclization can be carried out such that a divergent pathway is observed that leads to azepine scaffolds.