Atropisomers of Cofacial Heteroaromatic Rings with Two Positive Charges. Derivatives of 1,8-Di(3‘-pyridyl)naphthalene

Abstract
The two nitrogen atoms in 1,8-di(3‘-pyridyl)naphthalene were quaternized by the addition of either benzyl or methyl groups to give dications; the latter was oxidatively converted to the di(6‘-pyridone). N-Oxidation gave the mono- and di-N-oxides. All these compounds in DMSO-d6 show antisyn atropisomerism at ambient temperatures by 1H NMR analysis; similar amounts of both diastereomers are present.