title: Nickel-catalyzed intramolecular [3 + 2 + 2] cycloadditions of alkylidenecyclopropanes. A straightforward entry to fused 6,7,5-tricyclic systems.
abstract: A highly diastereo- and chemoselective intramolecular nickel-catalyzed cycloaddition of alkene- and alkyne-tethered alkynylidenecyclopropanes is reported. The method constitutes the first fully intramolecular [3 + 2 + 2] alkylidenecyclopropropane cycloaddition occurring via a proximal cleavage of the cyclopropane and makes it possible to build relevant 6,7,5-tricyclic frameworks in a single-pot reaction. Importantly, the reaction outcome is highly dependent on the characteristics of the nickel ligands.
authors.affiliation: Centro Singular de Investigación en Química Biológica y Materiales Moleculares (CIQUS) and Departamento de Química Orgánica, Universidad de Santiago de Compostela , 15782 Santiago de Compostela, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: Saya
authors.forename: Israel
authors.initials: I
authors.lastname: Fernández
authors.forename: Fernando
authors.initials: F
authors.lastname: López
authors.forename: José L
authors.initials: JL
authors.lastname: Mascareñas
mesh_terms: D000475:Alkenes / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D061565:Cycloaddition Reaction; D003521:Cyclopropanes / Q000737:chemistry*; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D000480:Alkynes; D003521:Cyclopropanes; D006575:Heterocyclic Compounds, 3-Ring; D009532:Nickel