title: Lewis acid catalyzed [3 + 2] annulation of ketenimines with donor-acceptor cyclopropanes: an approach to 2-alkylidenepyrrolidine derivatives.
abstract: The [3 + 2] annulation reaction of C,C,N-trisubstituted ketenimines with donor-acceptor cyclopropanes bearing aryl, styryl and vinyl substituents at the C2 position, triggered by the Lewis acid Sc(OTf)3, supplies highly substituted pyrrolidines. Activated cyclopropanes fused to naphthalene and [1]benzopyrane nuclei are also suitable substrates in similar transformations, yielding partially saturated benz[g]indoles and [1]benzopyran[4,3-b]pyrroles. An intramolecular version of this ketenimine/cyclopropane [3 + 2] annulation has also been developed leading to the pyrrolo[2,1-a]isoindole framework.
authors.affiliation: Departamento de Química Orgánica, Universidad de Murcia, Facultad de Química, Regional Campus of International Excellence "Campus Mare Nostrum", Espinardo, 30100 Murcia, Spain. vidal@um.es.
authors.forename: Mateo
authors.initials: M
authors.lastname: Alajarin
authors.affiliation: Departamento de Química Orgánica, Universidad de Murcia, Facultad de Química, Regional Campus of International Excellence "Campus Mare Nostrum", Espinardo, 30100 Murcia, Spain. vidal@um.es.
authors.forename: Adrian
authors.initials: A
authors.lastname: Egea
authors.affiliation: Servicio Universitario de Instrumentación Científica, Universidad de Murcia, Regional Campus of International Excellence "Campus Mare Nostrum", Espinardo, 30100, Murcia, Spain.
authors.forename: Raul-Angel
authors.initials: RA
authors.lastname: Orenes
authors.affiliation: Departamento de Química Orgánica, Universidad de Murcia, Facultad de Química, Regional Campus of International Excellence "Campus Mare Nostrum", Espinardo, 30100 Murcia, Spain. vidal@um.es.
authors.forename: Angel
authors.initials: A
authors.lastname: Vidal