Ni-Catalyzed Intramolecular Enal-Alkyne [3+2] Reductive Cycloaddition

Significance

Structures containing carbocyclic five-membered rings are widespread in nature among the biologically active compounds of different classes. Despite the various methods existing for the construction of such compounds, the direct assembly of two acyclic unsaturated systems would be the most straightforward. Herein, a relatively simple and general process for the formation of cyclopentenols from alkynes and α,β-enones via Ni(0)-catalyzed [3+2] cycloaddition is reported. Starting from simple, readily available precursors, a number of structurally interesting polysubstituted cyclopentenols were prepared in good yields with moderate to good stereoselectivity.