A one-pot, three-component, Cu(I)-catalyzed coupling of primary hydrazines, 5-chloropentan-2-one,
and terminal alkynes was developed. The resulting 1-aza-6,7-dehydrotropanes compose
a new class of substances while related 1-azatropanes are scarcely described in literature
and closely resemble tropane alkaloids. Hydrogenation of the double bond in 1-aza-6,7-dehydrotropanes
triggered a rearrangement, involving a [1,3]-hydride shift, forming cyclic hydrazones.
Key words
multicomponent reactions - alkynes - hydrazines - ketones - copper catalysis - 1-azatropanes