Atropisomeric benzamides and naphthamides as chiral auxiliaries

Atropisomeric compounds whose chirality resides in a rotationally restricte d aryl-CONR2 bond may be employed as chiral auxiliaries. The electron-withd rawing amide group causes problems in the diastereoselective functionalisat ion of enolates derived from atropisomeric phenyl esters, but a strategy ba sed on atroposelective nucleophilic addition to a chiral aldehyde followed by stereospecific [3,3] sigmatropic rearrangement allows atropisomeric naph thamides to be used as auxiliaries. The auxiliaries are resolved by dynamic resolution during aminal formation using a proline-derived diamine.