title: H-bond-assisted regioselective (cis-1) intramolecular nucleophilic addition of the hydroxyl group to [60]fullerene.
abstract: The one-step reaction of 2,6-dihydroxyphenylmethyl ketone and sarcosine with [60]fullerene in refluxing chlorobenzene affords, in a totally regioselective process, the cis-1 bicyclic-fused organofullerene through a new intramolecular nucleophilic addition of one hydroxy group to the fullerene double bond. Experimental findings reveal the presence of a methyl group on C-2 of the pyrrolidine ring as an essential requirement for the cyclization process, whereas the existence of a H-bond between a second hydroxylic group and the nitrogen atom of the pyrrolidine ring seems to favor the approaching geometry without determining the reaction outcome. Theoretical calculations using the two-layered ONIOM approach and density functional theory support the experimental findings, predicting the strong impact that the presence of the methyl substituent on the C-2 of the pyrrolidine ring has on the molecular geometry and, hence, on the intramolecular cyclization process.
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Izquierdo
authors.forename: Sílvia
authors.initials: S
authors.lastname: Osuna
authors.forename: Salvatore
authors.initials: S
authors.lastname: Filippone
authors.forename: Angel
authors.initials: A
authors.lastname: Martín-Domenech
authors.forename: Miquel
authors.initials: M
authors.lastname: Solà
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín