title: Palladium-catalyzed stereoconvergent formylation of (E/Z)-β-bromo-β-fluorostyrenes: straightforward access to (Z)-α-fluorocinnamic aldehydes and (Z)-β-fluorocinnamic alcohols.
abstract: We report here the stereoconvergent formylation of (E/Z)-β-bromo-β-fluorostyrene mixtures with carbon monoxide and sodium formate catalyzed by palladium. Optimization of reaction conditions leads to the corresponding pure (Z)-α-fluorocinnamaldehydes in good yields. The reaction was extended to styrenes bearing electro-attracting or electro-donating groups. The obtained α-fluoroaldehydes were smoothly reduced to the corresponding (Z)-β-fluorocinnamic alcohol by NaBH(4). The reaction could be performed on functionalized substrates as demonstrated by the access to the glucoside of β-fluoroconiferyl alcohol, (Z)-β-fluoroconiferin, a strong inhibitor of lignin polymerization.
authors.affiliation: USR CNRS 3290, Miniaturisation pour la Synthèse, l'Analyse et la Protéomique, Université de Lille 1, Sciences et Technologies, 59655 Villeneuve d’Ascq, France.
authors.forename: Rajae
authors.initials: R
authors.lastname: Zemmouri
authors.forename: Mohammed
authors.initials: M
authors.lastname: Kajjout
authors.forename: Yves
authors.initials: Y
authors.lastname: Castanet
authors.forename: Said
authors.initials: S
authors.lastname: Eddarir
authors.forename: Christian
authors.initials: C
authors.lastname: Rolando
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives* / Q000737:chemistry; D002384:Catalysis; D054879:Halogenation; D006859:Hydrogen / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D020005:Propanols / Q000737:chemistry*; D013237:Stereoisomerism; D013343:Styrenes / Q000737:chemistry*
chemical_list: D020005:Propanols; D013343:Styrenes; D010165:Palladium; D000171:Acrolein; D006859:Hydrogen; C012843:cinnamaldehyde; C020722:cinnamyl alcohol