Regioselective copper-catalyzed dearomative alkynylation of <i>N</i> -alkyl nicotinate and isoquinoline salts

This report describes a copper-catalyzed, dearomative alkynylation of <i>N</i>-alkyl pyridinium and isoquinolinium salts with readily available terminal alkynes. The reaction proceeds under mild conditions to afford a range of six-membered N-heterocyclic scaffolds in moderate to good yields with high regioselectivity. These products serve as valuable synthetic intermediates for the construction of complex nitrogen-containing heterocycles.