Conformationally interlocked amides: Remote asymmetric induction by mechanical transfer of stereochemical information

The axial conformation of an aromatic tertiary amide group may be powerfully influenced by an adjacent stereogenic centre. Because the amide axis can also control the formation of new chiral centres, the amide can act as a 'relay centre' for the transmission of stereochemical information. Conformational interlocking of adjacent amide groups on an aromatic ring means that a pair of amide groups can be used in series to mediate asymmetric induction between remote stereogenic centres, for example those lying para across an aromatic ring.