Nickel-Catalyzed Carbonylation of Cyclopropanol with Benzyl Bromide for Multisubstituted Cyclopentenone Synthesis

Abstract

Herein, we reported a Ni-catalyzed carbonylation of cyclopropanol with benzyl bromide to afford multisubstituted cyclopentenone under 1 atm of CO. The reaction proceeds through cascade carbonylation of benzyl bromides, followed by generation of nickel homoenolate from cyclopropanols via β-C elimination to afford 1,4-diketones, which undergoes intramolecular Aldol condensation to furnish highly substituted cyclopentenone derivatives in moderate to good yields. The reaction exhibits high functional group tolerance with broad substrate scope.

Recent Advances in Nonprecious Metal Catalysis

“…The synthesis of 2,3-diaryl-substituted cyclopentenones was demonstrated by Chen and co-workers using nickel-catalyzed carbonylation of benzyl bromides with cyclopropanol (Scheme ). 20 Commercially available NiCl 2 •DME and 4,4′-dimethylbipyridine were used for the generation of the active catalyst. LiCl was found to be a necessary additive to perform the carbonylation using atmospheric CO. A range of (hetero)arylsubstituted cyclopropanols and primary benzyl bromides bearing various electron-withdrawing and -donating aryl groups were tolerated in the reaction.…”

Nickel-Catalyzed Carbonylative Synthesis of α,β-Unsaturated Thioesters from Vinyl Triflates and Arylsulfonyl Chlorides

“…Nickel, an abundant non-noble metal with special catalytic activity, would be an ideal choice. As expected, several novel reports by using nickel as the catalyst in carbonylation reactions have been developed . On the basis of our previous studies on nickel-catalyzed carbonylation reactions, ,, we assumed that the combination of a nickel catalyst with Mo­(CO) 6 would be a good combination to minimize the possibility for highly toxic and inactive Ni­(CO) 4 species formation.…”

Intermolecular Pauson–Khand-Type Reaction of Vinyl Iodides with Alkynes and a CO Surrogate

“…Other transition-metal-catalyzed approaches which form these important cyclopentenones take mechanistically distinct pathways. , Examples of this include the transition-metal-catalyzed cyclization of α,β-unsaturated carbonyls with alkynes by Ogoshi, Montgomery, , Barluenga, , and others. − Previously, our group has also reported a distinct entry into this class of compounds. We used palladium catalysis to engage α,β-unsaturated acid chlorides and internal alkynes in the presence of a hydrosilane, as a hydride source, to form cyclopentenones through a molecular shuffling approach (Scheme B) .…”

“…24 Other transition-metal-catalyzed approaches which form these important cyclopentenones take mechanistically distinct pathways. 62,63 Examples of this include the transition-metalcatalyzed cyclization of α,β-unsaturated carbonyls with alkynes by Ogoshi, 64 Montgomery, 65,66 Barluenga,67,68 and others. 69−73 Previously, our group has also reported a distinct entry into this class of compounds.…”