ENANTIOMERS OF AMINES?

The ground-state structure of  an asymmetrically substituted amine NR¹R²R³ is closely related to that of an asymmetric carbon centre.  Amines are pyramidal, so that the lone pair effectively takes the position of the fourth substituent.  Once again the structure is chiral, capable of existence in two mirror-image forms (see below).
 
 

However, the two forms are not enantiomers, because they are not isomers.  They interconvert at room temperature and are therefore different forms of the same molecule.  During the interconversion they pass through the structure below, which is planar and therefore achiral.  Thus the amine has an accessible achiral conformation, a reliable indication that a molecule will not have an enantiomer.
 
 

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