The attractive features of the metal-free (free base) porphyrin inner core has lately drawn attention in the fields of catalysis , sensing , supramolecular assemblies , and absolute configuration determination. Typically, the imine and amine units of porphyrins are not involved in intermolecular interactions due to the planar nature of the macrocycle. However, the existing methods of ring puckering by steric strain can cause a degree of outwards orientation of the inner pyrrolic entities, making these positions more basic and accessible to substrates. Even though porphyrins adopt a saddle-shaped 3D conformation creating an 'active center' in the core, only the saddle-deformation alongside chiral guest interactions is not enough to drive the inner N-H signal to split during the 1 H NMR e.e. analysis. For example, Bz2oxP has a saddle shape and belongs to the C2v point-group notation with two mirror planes diagonally dividing all pyrroles (Figure ). The symmetrical nature of Bz2oxP does not permit the e.e. discrimination using the inner core. However, the N-H signal shifts to the lower field of the spectrum due to the non-covalent interactions nevertheless remain isochronous. Figure . Top: representation of pro-CSA's (blue above the plane, redbelow); Middle: with symmetry elements (Mirror plane σ and rotation axis Cn); Bottom: the key units used for e.e. detection by H NMR; a) Bz2oxP highlighting -H splitting; b) newly designed 22-P receptor system with chiral discrimination by N-H; c) All possible P atropisomers with corresponding point groups, N-H signals, and magnitude of splitting; see more detail in Figure .