Unexpected racemization behavior of 8,8′-dialkyl-1,1′-biisoquinoline

Abstract The racemization behavior of a series of atropisomeric 8,8′-dialkyl-1,1′-biisoquinolines, in which methyl, ethyl, and isopropyl groups are introduced for enhancing the transannular steric hindrance, is reported. Contrary to prior expectations, their configurational stability was inversely proportional to the steric size of the alkyl groups.