title: Structure, stereodynamics and absolute configuration of the atropisomers of hindered arylanthraquinones.
abstract: Anthraquinone substituted by 2-methyl-1-naphthyl groups in positions 1,8 yields syn (meso) and anti (racemic) isomers (red and yellow colored, respectively) that interconvert with a barrier of 35.4 kcal mol(-1) in solution. Their structures were identified by NOE experiments in solution and X-ray diffraction in the solids. The racemic anti form (C(2) point group) entails two atropisomers that were separated by enantioselective HPLC: the absolute configuration was assigned by TD-DFT simulation of the ECD spectrum. Two atropisomers were also separated and assigned in the case of anthraquinone bearing a single 2-methyl-1-naphthyl substituent in position 1.
authors.affiliation: Department of Organic Chemistry A. Mangini, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy.
authors.forename: Lodovico
authors.initials: L
authors.lastname: Lunazzi
authors.forename: Michele
authors.initials: M
authors.lastname: Mancinelli
authors.forename: Andrea
authors.initials: A
authors.lastname: Mazzanti