co-crystallization with a tartaric acid derivative is a successful examples (Fig. 3.2a)
[23], and planar chiral (S p )- and (R p )-[2.2]PHANEPHOS are the commercially
available chiral ligands for the transition metal-catalyzed asymmetric reactions.
Pd 2 (dba) 3 /[2.2]PHANEPHOS-catalyzed amination of rac-pseudo-ortho-dibromo
[2.2]paracyclophane enabled the kinetic resolution [24] for obtaining the
enantioenriched pseudo-ortho-dibromo[2.2]paracyclophane (Fig. 3.2b). Optical resolutions of rac-4-bromo-12-hydroxy[2.2]paracyclophane [25], rac-pseudo-orthodihydroxy[2.2]paracyclophane (rac-PHANOL) [26], and rac-pseudo-orthodihydroxymethyl[2.2]paracyclophane [27] were achieved by a diastereomer method
using chiral camphanic acid chloride as the chiral auxiliary; the optical resolution of
PHANOL is shown in Fig. 3.2c as a representative example. The enzyme-catalyzed
kinetic resolutions of rac-pseudo-ortho-disubstituted [2.2]paracyclophanes were
also reported [28–30], and the representative example is shown in Fig. 3.2d. Optical
resolution of rac-pseudo-ortho-dibromo[2.2]paracyclophane was carried out in
Fig. 3.2 Representative optical resolutions of pseudo-ortho-disubstituted [2.2]paracyclophanes
3 Circularly Polarized Luminescence from Planar Chiral Compounds Based on. . .
33