10 Circularly Polarized Luminescence (CPL) Based on Planar …
369
Fig. 10.33 Optical resolution of 4,7,12,15-bis-(para)-pseudo-meta-type tetrasubstituted [2.2]paracyclophane and the transformations
Diastereomer approach using (1S,4R)-(-)-camphanic chloride enabled the optical
resolution of the bis-(para)-pseudo-meta-type tetrasubstituted [2.2]paracyclophane
(Fig. 10.33). The resulting diastereomers (R p ,1S,4R)-70 and (S p ,1S,4R)-70 were
separated by simple column chromatography using SiO 2 . The reaction of 70
with KOH afforded the bisphenol and the next reaction with trifluoromethanesulfonic anhydride produced enantiopure bis-(para)-pseudo-meta-type tetrasubstituted
[2.2]paracyclophanes 71. These enantiomers are also used as the chiral building
blocks for various CPL emitters.
10.7 Conclusion
In summary, the authors have focused on the planar chirality of [2.2]paracyclophane and the intense CPL emission from the enantiopure [2.2]paracyclophanebased molecules in this chapter. Their optical resolution methods basically consisted
of diastereomer resolution methods using the common chiral auxiliaries such
as (1R,2S,5R)-(-)-menthyl-p-toluenesulfinate and (1S,4R)-(-)-camphanic chloride
369
Fig. 10.33 Optical resolution of 4,7,12,15-bis-(para)-pseudo-meta-type tetrasubstituted [2.2]paracyclophane and the transformations
Diastereomer approach using (1S,4R)-(-)-camphanic chloride enabled the optical
resolution of the bis-(para)-pseudo-meta-type tetrasubstituted [2.2]paracyclophane
(Fig. 10.33). The resulting diastereomers (R p ,1S,4R)-70 and (S p ,1S,4R)-70 were
separated by simple column chromatography using SiO 2 . The reaction of 70
with KOH afforded the bisphenol and the next reaction with trifluoromethanesulfonic anhydride produced enantiopure bis-(para)-pseudo-meta-type tetrasubstituted
[2.2]paracyclophanes 71. These enantiomers are also used as the chiral building
blocks for various CPL emitters.
10.7 Conclusion
In summary, the authors have focused on the planar chirality of [2.2]paracyclophane and the intense CPL emission from the enantiopure [2.2]paracyclophanebased molecules in this chapter. Their optical resolution methods basically consisted
of diastereomer resolution methods using the common chiral auxiliaries such
as (1R,2S,5R)-(-)-menthyl-p-toluenesulfinate and (1S,4R)-(-)-camphanic chloride