10 Circularly Polarized Luminescence (CPL) Based on Planar …
349
Aly and Brown 2009; Paradies 2011). The planar chirality of [2.2]paracyclophane
is well-known in the fields of organic chemistry and organometallic chemistry, and
planar chiral [2.2]paracyclophanes have been utilized as chiral auxiliaries and chiral
ligands. However, until recently, the planar chirality of [2.2]paracyclophane has been
ignored in the fields of polymer chemistry and materials chemistry until recently. In
2012, a new optical resolution method was developed for pseudo-ortho-disubstituted
[2.2]paracyclophane, and the transformation and polymerization of the enantiopure
[2.2]paracyclophanes were reported (Morisaki et al. 2012a, b). The resulting optically
active polymer emitted CPL (Morisaki et al. 2012).
This chapter highlights and introduces the recent results on the synthesis of enantiopure disubstituted and tetrasubstituted [2.2]paracyclophanes. The preparation of
optically active molecules based on the [2.2]paracyclophanes for their application in
the fields of polymer and materials chemistry as the CPL emitters is also described.
10.3 Synthesis of Enantiopure Disubstituted
[2.2]Paracyclophane and Optically Active π-Stacked
Molecules
Optical resolution routes of mono-substituted [2.2]paracyclophanes were developed, and various enantiopure ortho-, pseudo-geminal-, and syn-latero-disubstituted
[2.2]paracyclophanes were prepared (Cram and Allinger 1955; Rozenberg et al.
2004; Rowlands 2008; Gibson and Knight 2003; Aly and Brown 2009; Paradies
2011). In addition, several synthetic routes to the syntheses of enantiopure disubstituted [2.2]paracyclophanes, e.g., pseudo-ortho-disubstituted [2.2]paracyclophanes,
have been reported (Pye et al. 1997; Rossen et al. 1997; Zhuravsky et al. 2008;
Jiang and Zhao 2004; Jones et al. 2003; Pamperin et al. 1997; Pamperin et al.
1998; Braddock et al. 2002), as shown in Fig. 10.6. A representative example is
the synthesis of enantiopure pseudo-ortho-bis(diarylphosphino)[2.2]paracyclophane
(Ph-PHANEPHOS) (Fig. 10.6a) (Pye et al. 1997). The resulting (S p )- and (R p )Ph-PHANEPHOS are the commercially available chiral ligands for the transition metal-catalyzed asymmetric reactions. This PHANEPHOS makes it possible
to produce enantioenriched pseudo-ortho-dibromo[2.2]paracyclophane (Fig. 10.6b)
by kinetic resolution (Rossen et al. 1997). Synthesis of optically active 4bromo-12-hydroxy[2.2]paracyclophane (Zhuravsky et al. 2008), pseudo-orthodihydroxy[2.2]paracyclophane (PHANOL) (Jiang and Zhao 2004), and pseudoortho-dihydroxymethyl[2.2]paracyclophane (Jones et al. 2003) were successfully
synthesized by using chiral camphanic acid chloride as the chiral auxiliary; for
example, Fig. 10.6c shows the optical resolution of PHANOL racemate. The enzymepromoted kinetic resolutions of pseudo-ortho-disubstituted [2.2]paracyclophanes
have also been developed (Pamperin et al. 1997, 1998; Braddock et al. 2002).
A practical route to the optical resolution of pseudo-orthodibromo[2.2]paracyclophane was reported in 2012, in which (1R,2S,5R)-(-)-menthyl
349
Aly and Brown 2009; Paradies 2011). The planar chirality of [2.2]paracyclophane
is well-known in the fields of organic chemistry and organometallic chemistry, and
planar chiral [2.2]paracyclophanes have been utilized as chiral auxiliaries and chiral
ligands. However, until recently, the planar chirality of [2.2]paracyclophane has been
ignored in the fields of polymer chemistry and materials chemistry until recently. In
2012, a new optical resolution method was developed for pseudo-ortho-disubstituted
[2.2]paracyclophane, and the transformation and polymerization of the enantiopure
[2.2]paracyclophanes were reported (Morisaki et al. 2012a, b). The resulting optically
active polymer emitted CPL (Morisaki et al. 2012).
This chapter highlights and introduces the recent results on the synthesis of enantiopure disubstituted and tetrasubstituted [2.2]paracyclophanes. The preparation of
optically active molecules based on the [2.2]paracyclophanes for their application in
the fields of polymer and materials chemistry as the CPL emitters is also described.
10.3 Synthesis of Enantiopure Disubstituted
[2.2]Paracyclophane and Optically Active π-Stacked
Molecules
Optical resolution routes of mono-substituted [2.2]paracyclophanes were developed, and various enantiopure ortho-, pseudo-geminal-, and syn-latero-disubstituted
[2.2]paracyclophanes were prepared (Cram and Allinger 1955; Rozenberg et al.
2004; Rowlands 2008; Gibson and Knight 2003; Aly and Brown 2009; Paradies
2011). In addition, several synthetic routes to the syntheses of enantiopure disubstituted [2.2]paracyclophanes, e.g., pseudo-ortho-disubstituted [2.2]paracyclophanes,
have been reported (Pye et al. 1997; Rossen et al. 1997; Zhuravsky et al. 2008;
Jiang and Zhao 2004; Jones et al. 2003; Pamperin et al. 1997; Pamperin et al.
1998; Braddock et al. 2002), as shown in Fig. 10.6. A representative example is
the synthesis of enantiopure pseudo-ortho-bis(diarylphosphino)[2.2]paracyclophane
(Ph-PHANEPHOS) (Fig. 10.6a) (Pye et al. 1997). The resulting (S p )- and (R p )Ph-PHANEPHOS are the commercially available chiral ligands for the transition metal-catalyzed asymmetric reactions. This PHANEPHOS makes it possible
to produce enantioenriched pseudo-ortho-dibromo[2.2]paracyclophane (Fig. 10.6b)
by kinetic resolution (Rossen et al. 1997). Synthesis of optically active 4bromo-12-hydroxy[2.2]paracyclophane (Zhuravsky et al. 2008), pseudo-orthodihydroxy[2.2]paracyclophane (PHANOL) (Jiang and Zhao 2004), and pseudoortho-dihydroxymethyl[2.2]paracyclophane (Jones et al. 2003) were successfully
synthesized by using chiral camphanic acid chloride as the chiral auxiliary; for
example, Fig. 10.6c shows the optical resolution of PHANOL racemate. The enzymepromoted kinetic resolutions of pseudo-ortho-disubstituted [2.2]paracyclophanes
have also been developed (Pamperin et al. 1997, 1998; Braddock et al. 2002).
A practical route to the optical resolution of pseudo-orthodibromo[2.2]paracyclophane was reported in 2012, in which (1R,2S,5R)-(-)-menthyl