Among various target chemicals, cyclic carbonate is a
promising one and has been widely used as a starting material
for polycarbonate resin,2 an electrolyte for lithium ion
batteries,3 and an inert solvent.4 Conventionally, cyclic
carbonates have been produced by using phosgene or its
derivatives;5 however, this process has considerable drawbacks,
such as use of highly toxic phosgene, and coproduction of a
large amount of salts by the neutralization. Various alternative
methodologies with catalysts,6 such as oxidation of olefins with
CO2, cycloaddition of CO2 to epoxides, oxidative carbonylation
of diols, transesterification of diols with dialkyl carbonate, and
the reaction of diols with urea, have been proposed. Among
these methodologies, cycloaddition of CO2 to epoxides has
been the most investigated owing to its green process, and
many effective catalysts have been reported. However, this
process has problems that starting materials such as epoxides
and oxetanes demand peculiar handling techniques because of
their high reactivity or toxicity, and oxetanes are prepared by
the perplexing method.