New anionic cyclization of 4- and 5-alkynylamines: Synthesis of 2-Benzylidene pyrrolidines and piperidines

Article abstract of DOI:10.3987/COM-95-S50

Treatment of 4- and 5-alkynylamines with 0.5-1.2 equiv. of butyllithium brought about a facile anionic cyclization, giving the corresponding enamine pyrrolidines and piperidines having an exo double bond in high yields. Treatment of 4-alkynamides with lit