title: Stereodivergent synthesis of chiral fullerenes by [3 + 2] cycloadditions to C₆₀.
abstract: A wide range of new dipoles and catalysts have been used in 1,3-dipolar cycloadditions of N-metalated azomethine ylides onto C60 yielding a full stereodivergent synthesis of pyrrolidino[60]fullerenes with complete diastereoselectivities and very high enantioselectivities. The use of less-explored chiral α-iminoamides as starting 1,3-dipoles leads to an interesting double asymmetric induction resulting in a matching/mismatching effect depending upon the absolute configuration of the stereocenter in the starting α-iminoamide. An enantioselective process was also found in the retrocycloaddition reaction as revealed by mass spectrometry analysis on quasi-enantiomeric pyrrolidino[60]fullerenes. Theoretical DFT calculations are in very good agreement with the experimental data. On the basis of this agreement, a plausible reaction mechanism is proposed.
authors.affiliation: Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense , E-28040 Madrid, Spain.
authors.forename: Enrique E
authors.initials: EE
authors.lastname: Maroto
authors.forename: Salvatore
authors.initials: S
authors.lastname: Filippone
authors.forename: Margarita
authors.initials: M
authors.lastname: Suárez
authors.forename: Roberto
authors.initials: R
authors.lastname: Martínez-Álvarez
authors.forename: Abel
authors.initials: A
authors.lastname: de Cózar
authors.forename: Fernando P
authors.initials: FP
authors.lastname: Cossío
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín