title: Tandem processes promoted by a hydrogen shift in 6-arylfulvenes bearing acetalic units at ortho position: a combined experimental and computational study.
abstract: 6-Phenylfulvenes bearing (1,3-dioxolan or dioxan)-2-yl substituents at ortho position convert into mixtures of 4- and 9-(hydroxy)alkoxy-substituted benz[f]indenes as result of cascade processes initiated by a thermally activated hydrogen shift. Structurally related fulvenes with non-cyclic acetalic units afforded mixtures of 4- and 9-alkoxybenz[f]indenes under similar thermal conditions. Mechanistic paths promoted by an initial [1,4]-, [1,5]-, [1,7]- or [1,9]-H shift are conceivable for explaining these conversions. Deuterium labelling experiments exclude the [1,4]-hydride shift as the first step. A computational study scrutinized the reaction channels of these tandem conversions starting by [1,5]-, [1,7]- and [1,9]-H shifts, revealing that this first step is the rate-determining one and that the [1,9]-H shift is the one with the lowest energy barrier.
authors.affiliation: Departamento de Química Orgánica, Universidad de Murcia, Facultad de Química, Regional Campus of International Excellence "Campus Mare Nostrum", Espinardo, 30100 Murcia (Spain).
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).
authors.forename: Marta
authors.initials: M
authors.lastname: Marin-Luna
authors.affiliation: University Centre of Defence at the Spanish Air Force Academy, Base Aerea de San Javier, C/ Coronel López Peña s/n, 30720, Santiago de la Ribera, Murcia, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Sanchez-Andrada
authors.affiliation: Departamento de Química Orgánica, Universidad de Murcia, Facultad de Química, Regional Campus of International Excellence "Campus Mare Nostrum", Espinardo, 30100 Murcia (Spain).
authors.forename: Angel
authors.initials: A
authors.lastname: Vidal
keywords: DFT calculations; acetal; benzindenes; fulvene; hydrogen shift