Access to 2-Alkyl/Aryl-4-(1)-Quinolones via Orthogonal "NH" Insertion into -Haloaryl Ynones: Total Synthesis of Bioactive Pseudanes, Graveoline, Graveolinine, and Waltherione F.

An efficient one-pot synthesis of 4-(1)-quinolones through an orthogonal engagement of diverse -haloaryl ynones with ammonia in the presence of Cu(I), involving tandem Michael addition and ArCsp-N coupling, is presented. The substrate scope of this convenient protocol, wherein ammonium carbonate acts as both an in situ ammonia source and a base toward diverse 2-substituted 4-(1)-quinolones, has been mapped and its efficacy validated through concise total synthesis of bioactive natural products pseudanes (IV, VII, VIII, and XII), graveoline, graveolinine, and waltherione F.