Chemistry Reference
In-Depth Information
employed as a catalyst or a ligand to achieve unique asymmetric catalysis although the
yield and enantioselectivity are not comparable to those obtained by the conventional
catalysis of small molecules. The rational design of monomers would lead to the devel-
opment of novel helically chiral polymers that will work as more effi cient and selective
catalysts.
In enantiomer-selective polymerization, high enantiomer selectivity has been achieved
in the polymerization of olefi nic monomers and the ring-opening polymerization of
cyclic monomers. However, the problem that inevitably arises in enantiomer-selective
polymerization via kinetic resolution is that the conversion of the starting monomer is
always lower than 50% since the only one enantiomer can be used for polymerization.
In this regard, the relatively new concept of DKR polymerization offers a promising
answer to the problem, providing an effi cient route for the one-pot synthesis of chiral
polymers from racemic nonnatural monomers.
As described in this chapter, a broad range of synthetic methodologies for asymmetric
polymerization have been developed by taking full advantage of asymmetric organic
synthesis. Despite such a remarkable progress, however, novel polymerization systems
that will further expand the scope of asymmetric polymerization are still needed since
the current performance of the optically active polymers as practical functional materials
is not satisfactory. Therefore, future challenges include the development of novel cata-
lytic systems and monomers, which can construct complex polymeric architectures, and
their applications as truly useful functional polymeric materials. Asymmetric polymer-
ization is distinctly a growing fi eld of polymer chemistry. A number of novel synthetic
methodologies to obtain optically active polymers will be developed to expand the effi -
ciency and versatility of asymmetric polymerization. It is our hope that the present
review will induce new interests in asymmetric polymerization.
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