title: Iron-Catalyzed Cyclization of Alkynols with Diorganyl Diselenides: Synthesis of 2,5-Dihydrofuran, 3,6-Dihydro-2H-pyran, and 2,5-Dihydro-1H-pyrrole Organoselanyl Derivatives.
abstract: An iron-catalyzed system, using diorganyl diselenides as an organoselenium source, was used for the cyclization of 1,4-butyne-diols in the preparation of 3,4-bis(organoselanyl)-2,5-dihydrofurans. The optimized reaction conditions are compatible with many functional groups in 1,4-butyne-diols and diorganyl diselenides. In addition, this catalyst system was also efficient with diorganyl disulfides, but it did not work for diorganyl ditellurides. The same reaction conditions were also extended to pentyne-1,5-diol for the preparation of 4,5-bis(organoselanyl)-3,6-dihydro-2H-pyrans and to 4-amino-butynol for the preparation of 2,5-dihydro-1H-pyrrole derivatives. The synthetic utility of these heterocycles was studied using 5-bis(organoselanyl)-3,6-dihydro-2H-pyrans as substrate in a Kumada-type cross-coupling reaction.
authors.affiliation: †Laboratório de Síntese, Reatividade, Avaliação Farmacológica e Toxicológica de Organocalcogênios and ‡Laboratório de Materiais Inorgânicos, CCNE, UFSM, Santa Maria, Rio Grande do Sul, Brazil, 97105-900.
authors.forename: Kamila K
authors.initials: KK
authors.lastname: Casola
authors.affiliation: †Laboratório de Síntese, Reatividade, Avaliação Farmacológica e Toxicológica de Organocalcogênios and ‡Laboratório de Materiais Inorgânicos, CCNE, UFSM, Santa Maria, Rio Grande do Sul, Brazil, 97105-900.
authors.forename: Davi F
authors.initials: DF
authors.lastname: Back
authors.affiliation: †Laboratório de Síntese, Reatividade, Avaliação Farmacológica e Toxicológica de Organocalcogênios and ‡Laboratório de Materiais Inorgânicos, CCNE, UFSM, Santa Maria, Rio Grande do Sul, Brazil, 97105-900.
authors.forename: Gilson
authors.initials: G
authors.lastname: Zeni
mesh_terms: D000605:Amino Alcohols / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D015394:Molecular Structure; D016566:Organoselenium Compounds / Q000737:chemistry*; D011714:Pyrans / Q000138:chemical synthesis / Q000737:chemistry*; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C000604324:3,6-dihydro-2H-pyran; D000605:Amino Alcohols; D005663:Furans; D016566:Organoselenium Compounds; D011714:Pyrans; D011758:Pyrroles; C089584:4-aminobutanol; D007501:Iron; C000604323:2,5-dihydrofuran; C000604325:2,5-dihydro-1H-pyrrole