title: Formal cycloaddition of disubstituted ketenes with 2-oxoaldehydes catalyzed by chiral N-heterocyclic carbenes.
abstract: Chiral N-hetereocyclic carbenes were found to be efficient catalysts for the formal [2 + 2] cycloaddition reactions of alkyl(aryl)ketenes with 2-oxoaldehydes to afford beta-lactones with alpha-quaternary-beta-tertiary stereocenters in high yields with good diastereoselectivities and excellent enantioselectivities (up to 99% ee). Both alkyl(aryl)ketenes and diarylketene worked well in this reaction.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Laboratory of Chemical Biology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Lin
authors.initials: L
authors.lastname: He
authors.forename: Hui
authors.initials: H
authors.lastname: Lv
authors.forename: Yan-Rong
authors.initials: YR
authors.lastname: Zhang
authors.forename: Song
authors.initials: S
authors.lastname: Ye
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D005030:Ethylenes / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D005030:Ethylenes; D007659:Ketones; C030011:carbene; C008223:ketene; D008697:Methane