The orientation of Ar-C, Ar-N and Ar-O bonds in biaryls, N,N'-diarylureas and diaryl ethers (whose conformers are distinguishable by NMR) may be controlled with a selectivity up to >95 : 5 by an adjacent stereogenic centre; the selectivity may be greater when a second stereogenic axis is inserted between the controlling centre and the slowly rotating bond.

Atropisomeric biaryl aldehydes undergo diastereoselective condensation with (−)-ephedrine and with a proline-derived diamine, with selectivity highly dependent on solvent, temperature and reaction conditions. Levels of thermodynamic control up to 5:1 may be obtained by heating the diamine with the aldehyde in a sealed tube. Alternatively, crystallisation-induced dynamic transformation allows isolation of a single diastereoisomer in up to 85% yield. Hydrolysis and reduction of the major diastereoisomeric product of the reaction yields atropisomeric biaryls in >99:1 enantiomeric ratios.