1 research outputs found
Povarov Reaction of Cycloiminium Formed in Situ via Hydroamination Cycloisomerization of Homopropargylic Amines with Electron-Rich Olefins
A new,
one-pot cascade reaction of homopropargylic amines with
electron-rich olefins is developed in the presence of Cu(OTf)<sub>2</sub> and affords a series of octahydrofuro[3,2-<i>c</i>]pyrrolo[1,2-<i>a</i>]quinoline derivatives in yields of
38–80%. This reaction proceeds through an intramolecular hydroamination
cyclization of homopropargylic amine to generate a highly reactive
cycloenamine intermediate in situ that subsequently isomerizes to
the cycloiminium cation followed by the Povarov-type reaction with
dihydrofuran, dihydropyran, or dihydropyrrole. Notably, the Al<sub>2</sub>O<sub>3</sub> additive plays a key role for the effective
inhibition of competitive self-dimerization of homoproargylic amines