title: Stereo- and Chemodivergent NHC-Promoted Functionalisation of Arylalkylketenes with Chloral.
abstract: Stereo- and chemodivergent enantioselective reaction pathways are observed upon treatment of alkylarylketenes and trichloroacetaldehyde (chloral) with N-heterocyclic carbenes, giving selectively either β-lactones (up to 88:12 dr, up to 94 % ee) or α-chloroesters (up to 94 % ee). Either 2-arylsubstitution or an α-branched iPr alkyl substituent within the ketene favours the chlorination pathway, allowing chloral to be used as an electrophilic chlorinating reagent in asymmetric catalysis.
authors.affiliation: EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST (UK) http://ch-www.st-andrews.ac.uk/staff/ads/group/|Current Address: Small Molecule Design and Development, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285 (USA).
authors.forename: James J
authors.initials: JJ
authors.lastname: Douglas
authors.affiliation: AstraZeneca, Pharmaceutical Development, Macclesfield, Cheshire, SK10 2NA (UK).
authors.forename: Gwydion
authors.initials: G
authors.lastname: Churchill
authors.affiliation: EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST (UK) http://ch-www.st-andrews.ac.uk/staff/ads/group/
authors.forename: Alexandra M Z
authors.initials: AM
authors.lastname: Slawin
authors.affiliation: Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV7 4AL (UK). d.j.fox@warwick.ac.uk.
authors.forename: David J
authors.initials: DJ
authors.lastname: Fox
authors.affiliation: EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST (UK) http://ch-www.st-andrews.ac.uk/staff/ads/group/. ads10@st-andrews.ac.uk.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Smith
keywords: asymmetric catalysis; chlorination reactions; ketenes; lactones; stereodivergent reactions