Enantioenriched Axially Chiral b-Diketimines: Determination of the IAN-amine Barrier to Atrop- isomerization

Abstract

Enantioenriched (>98% ee) b-diketimines derived from Isoquinoline and 2-Amino Naphthalene ('IAN-amines') were prepared.Thermal racemization of a series of R-IAN amines (R = NH 2 , NHMe, NMe 2 ) revealed a high barrier to atropisomerization (~30 kcal/mol) and its relative insensitivity to substitution at the aminonaphthalene nitrogen.Molecular mechanics calculations accurately predicted the observed relative substituent effects.