Dynamic resolution of atropisomeric amides using proline-derived imidazolines and ephedrine-derived oxazolidines

Condensation of atropisomeric tertiary 2-formyl naphthamides or 2-formyl benzamides with some chiral diamines and amino alcohols leads, via a dynamic resolution process, to single atropisomers of tertiary amides bearing chiral imidazolidines or oxazolidines. Hydrolysis of the new heterocycle competes a dynamic thermodynamic resolution of the starting aldehyde, and rapid reduction allows the isolation of atropisomeric amides bearing 2-hydroxymethyl substituents in enantiomerically enriched form. Evidence that the reactions are under thermodynamic control is presented.