New selective cyclizations of alk-4-ynals with primary amines and azoles:one-pot synthesis of 2-azolylpyrrolidines and 3-iminocyclopentenes

One-pot cyclization of alk-4-ynals with primary aliphatic amines and azoles in DMSO under the action of KOH affords 1-alkyl-2-azolyl-5-arylmethylidenepyrrolidines. Similar processes with lithium monoalkylamides in THF give rise to 3-iminocyclopentenes.