Direct introduction of acetylene moieties into azines by methodology

The N-oxides of azines 1a–g react with lithium and/or potassium acetylides to give the corresponding ethynylazines 2a–g. Reaction with lithium acetylide requires subsequent acylation of the intermediate anionic adduct for rearomatization whereas in the case of potassium acetylide, auto-aromatization takes place.