title: Rhodium-catalyzed (5+1) annulations between 2-alkenylphenols and allenes: a practical entry to 2,2-disubstituted 2H-chromenes.
abstract: Readily available alkenylphenols react with allenes under rhodium catalysis to provide valuable 2,2-disubstituted 2H-chromenes. The whole process, which involves the cleavage of one C-H bond of the alkenyl moiety and the participation of the allene as a one-carbon cycloaddition partner, can be considered a simple, versatile, and atom-economical (5+1) heteroannulation. The reaction tolerates a broad range of substituents both in the alkenylphenol and in the allene, and most probably proceeds through a mechanism involving a rhodium-catalyzed C-C coupling followed by two sequential pericyclic processes.
authors.affiliation: Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica 15782. Universidade de Santiago de Compostela (Spain).
authors.forename: Noelia
authors.initials: N
authors.lastname: Casanova
authors.forename: Andrés
authors.initials: A
authors.lastname: Seoane
authors.forename: José L
authors.initials: JL
authors.lastname: Mascareñas
authors.forename: Moisés
authors.initials: M
authors.lastname: Gulías
keywords: CH activation; allenes; annulations; reaction mechanisms; rhodium