Direct Condensation of Carboxylic Acids with Alcohols Catalyzed by Hafnium(IV) Salts
Kazuaki Ishihara,1
Suguru Ohara,2
Hisashi Yamamoto2*
In order to promote atom efficiency in synthesis and to
avoid the generation of environmental waste, the use of stoichiometric amounts of condensing reagents or excess substrates should be avoided.
In esterification, excesses of either carboxylic acids or alcohols are
normally needed. We show that the direct condensation of equimolar
amounts of carboxylic acids and alcohols can be achieved with the use
of hafnium(IV) salts, such as commercially available hafnium(IV)
chloride and hafnium(IV) tert-butoxide. The present method
can be applied to direct polyesterification and may be suitable for
large-scale operations.
1 Research Center for Advanced Waste and
Emission Management;
2 Graduate School of
Engineering, Nagoya University, Core Research for Evolutional Science
and Technology, Japan Science and Technology, Furo-cho, Chikusa, Nagoya
464-8603, Japan.
*
To whom correspondence should be addressed. E-mail:
yamamoto{at}cc.nagoya-u.ac.jp
