title: Synthesis of furan-3-carboxylic and 4-methylene-4,5-dihydrofuran-3-carboxylic esters by direct palladium iodide catalyzed oxidative carbonylation of 3-yne-1,2-diol derivatives.
abstract: A variety of 3-yne-1,2-diol derivatives 1, bearing a primary or secondary alcoholic group at C-1, have been efficiently converted into high value added furan-3-carboxylic esters 2 in one step by PdI(2)/KI-catalyzed direct oxidative carbonylation, carried out in alcoholic media under relatively mild conditions (100 °C under 40 atm of a 4/1 mixture of CO and air). Carbonylated furans 2 were obtained in fair to excellent isolated yields (56-93%) through a sequential 5-endo-dig heterocyclization-alkoxycarbonylation-dehydration process, using only oxygen as the external oxidant. Under similar conditions, 2-methyl-3-yne-1,2-diols 3, bearing a tertiary alcoholic group, afforded 4-methylene-4,5-dihydrofuran-3-carboxylates 4 in satisfactory yields (58-70%).
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università della Calabria, 87036 Arcavacata di Rende (CS), Italy. b.gabriele@unical.it
authors.forename: Bartolo
authors.initials: B
authors.lastname: Gabriele
authors.forename: Raffaella
authors.initials: R
authors.lastname: Mancuso
authors.forename: Vito
authors.initials: V
authors.lastname: Maltese
authors.forename: Lucia
authors.initials: L
authors.lastname: Veltri
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Salerno
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D004952:Esters; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry*; D007454:Iodides / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*
chemical_list: D000480:Alkynes; D002264:Carboxylic Acids; D004952:Esters; D005663:Furans; D007454:Iodides; C030011:carbene; D010165:Palladium; D008697:Methane