title: β-Olefination of 2-alkynoates leading to trisubstituted 1,3-dienes.
abstract: A phosphine-mediated olefination of 2-alkynoates with aldehydes forming 1,3-dienes with high E-selectivity and up to 88% yield is described. Reaction conditions are optimized and reactions are demonstrated for various aryl, alkyl, and alkenyl aldehydes and for ethyl 2-alkynoates with different substituents in the δ-position. Proof of concept is shown for the generation of a β,γ-unsaturated lactone by intramolecular olefination, and furthermore the use of the generated 1,3-dienes in the Diels-Alder reaction has been demonstrated.
authors.affiliation: Danish National Research Foundation: Centre for DNA Nanotechnology (CDNA) at Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark.
authors.forename: Mathias J
authors.initials: MJ
authors.lastname: Jacobsen
authors.forename: Erik Daa
authors.initials: ED
authors.lastname: Funder
authors.forename: Jacob R
authors.initials: JR
authors.lastname: Cramer
authors.forename: Kurt V
authors.initials: KV
authors.lastname: Gothelf
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D001547:Benzaldehydes / Q000737:chemistry; D015394:Molecular Structure; D010720:Phosphines / Q000737:chemistry
chemical_list: D000475:Alkenes; D001547:Benzaldehydes; D010720:Phosphines; C059341:2-chlorobenzaldehyde; C044646:phosphine