title: N-Heterocyclic Carbene-Catalyzed Diastereoselective Vinylogous Michael Addition Reaction of γ-Substituted Deconjugated Butenolides.
abstract: An efficient N-heterocyclic carbene (NHC)-catalyzed vinylogous Michael addition of deconjugated butenolides was developed. In the presence of 5 mol % of the NHC catalyst, both γ-alkyl- and aryl-substituted deconjugated butenolides undergo vinylogous Michael addition with various α, β-unsaturated ketones, esters, or nitriles to afford γ,γ-disubstituted butenolides containing adjacent quaternary and tertiary carbon centers in good to excellent yields with excellent diastereoselectivities. In this process, the free carbene is assumed to act as a strong Brønsted base to promote the conjugate addition.
authors.affiliation: School of Chemistry and Chemical Engineering, Shihezi University , Xinjiang Uygur Autonomous Region 832000, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Guo
authors.affiliation: School of Chemistry and Chemical Engineering, Shihezi University , Xinjiang Uygur Autonomous Region 832000, People's Republic of China.
authors.forename: Fen
authors.initials: F
authors.lastname: Xing
authors.affiliation: School of Chemistry and Chemical Engineering, Shihezi University , Xinjiang Uygur Autonomous Region 832000, People's Republic of China.
authors.forename: Guang-Fen
authors.initials: GF
authors.lastname: Du
authors.affiliation: Division of Chemical and Life Sciences & Engineering, and Catalysis Center, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia.
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Huang
authors.affiliation: School of Chemistry and Chemical Engineering, Shihezi University , Xinjiang Uygur Autonomous Region 832000, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Dai
authors.affiliation: School of Chemistry and Chemical Engineering, Shihezi University , Xinjiang Uygur Autonomous Region 832000, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: He