title: Trapping intermediates in an [8 + 2] cycloaddition reaction with the help of DFT calculations.
abstract: DFT calculations predict that the [8 + 2] cycloaddition reaction between ketenes and 8-azaheptafulvenes occurs stepwise through antiaromatic zwitterionic intermediates. With adequate modifications of both the electronic properties of the ketene and the reaction conditions, these elusive intermediates have been successfully trapped and fully characterized (X-ray), thus confirming the predicted stepwise nature of the transformation.
authors.affiliation: Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Marta L
authors.initials: ML
authors.lastname: Lage
authors.forename: Israel
authors.initials: I
authors.lastname: Fernández
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Sierra
authors.forename: M Rosario
authors.initials: MR
authors.lastname: Torres