A single Cu(II) catalyst without the addition of ligand or base couples a diverse range of nitrogen sources with alkynes and aldehydes bearing alkyl, halogenated, silyl, aryl, and heteroaryl groups. The first example of a copper-catalyzed alkynylation involving p-toluenesulfonamide provides high yields of N-Ts-protected propargylamines. The superior activity of copper(II) triflate also allows this three-component alkynylation to incorporate a ketone.

Difficult-to-access alkyl-substituted quinolines are formed directly from commercially available anilines, aldehydes, and alkynes bearing a variety of substituents. Copper(II) triflate catalyzes this three-component coupling without ligand, cocatalyst, solvent, or inert atmosphere. In addition, a two-component Povarov reaction forms 2,3-dialkyl quinolines under the same green conditions that enable the selective three-component synthesis of 2-alkyl quinolines as well as more common aryl quinolines.

No abstract

The copper salt promotes the three‐component coupling without the addition of ligand or base.