title: Organocatalytic functionalization of carboxylic acids: isothiourea-catalyzed asymmetric intra- and intermolecular Michael addition--lactonizations.
abstract: Tetramisole promotes the catalytic asymmetric intramolecular Michael addition-lactonization of a variety of enone acids, giving carbo- and heterocyclic products with high diastereo- and enantiocontrol (up to 99:1 dr, up to 99% ee) that are readily derivatized to afford functionalized indene and dihydrobenzofuran carboxylates. Chiral isothioureas also promote the catalytic asymmetric intermolecular Michael addition-lactonization of arylacetic acids and α-keto-β,γ-unsaturated esters, giving anti-dihydropyranones with high diastereo- and enantiocontrol (up to 98:2 dr, up to 99% ee).
authors.affiliation: EaStCHEM, School of Chemistry, University of St Andrews, St Andrews, UK.
authors.forename: Dorine
authors.initials: D
authors.lastname: Belmessieri
authors.forename: Louis C
authors.initials: LC
authors.lastname: Morrill
authors.forename: Carmen
authors.initials: C
authors.lastname: Simal
authors.forename: Alexandra M Z
authors.initials: AM
authors.lastname: Slawin
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Smith
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013890:Thiourea / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D011753:Pyrones; D013890:Thiourea