Inherent chirality

The term was first coined by Volker Boehmer in a 1994 review, to describe the chirality of calixarenes arising from their non-planar structure in 3-D space.

[1] Boehmer further explains this phenomenon by suggesting that if an inherently chiral calixarene macrocycle were opened up it would produce an "achiral linear molecule".

exists in solution as a racemic pair of enantiomers due to the curvature of an achiral polyene chain.

The first fully formulated definition of inherent chirality was published in 2004 by Mandolini and Schiaffino, (and later modified by Szumna):[4] inherent chirality arises from the introduction of a curvature in an ideal planar structure that is devoid of perpendicular symmetry planes in its bidimensional representation.

Inherently chiral alkenes have been synthesized through the use of dialkoxysilanes, with a large enough racemization barrier that enantiomers have been isolated.

Inherently chiral calixarene with XXYZ substitution pattern.
a) 2D representation of corannulene, b) 3D representation of corannulene bowl flip with C5 symmetry.
Inherently chiral paracyclophane, rendered chiral by the bromide substituent hindering rotation of the phenylene.
Chiral spiro ring system.