title: Vinyl dihydropyrans and dihydrooxazines: cyclizations of catalytic ruthenium carbenes derived from alkynals and alkynones.
abstract: A novel synthesis of 2-vinyldihydropyrans and dihydro-1,4-oxazines (morpholine derivatives) from alkynals and alkynones has been developed. The cyclizations require a mild generation of catalytic ruthenium carbenes from terminal alkynes and (trimethylsilyl)diazomethane followed by trapping with carbonyl nucleophiles. Mechanistic aspects of the new cyclizations are discussed.
authors.affiliation: Departamento de Química Orgánica y Centro Singular de Investigación en Química Biológica y Materiales Moleculares (CIQUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain) http://www.usc.es/gi1603/saa.
authors.forename: Fermín
authors.initials: F
authors.lastname: Cambeiro
authors.forename: Susana
authors.initials: S
authors.lastname: López
authors.forename: Jesús A
authors.initials: JA
authors.lastname: Varela
authors.forename: Carlos
authors.initials: C
authors.lastname: Saá
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D011143:Polyvinyl Chloride / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D000480:Alkynes; D012428:Ruthenium; D011143:Polyvinyl Chloride
keywords: alkynes; carbenes; cyclization; heterocycles; ruthenium