Synfacts 2011(4): 0444-0444  
DOI: 10.1055/s-0030-1259621
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart ˙ New York

Dehydrative Condensation of Dicarboxylic Acids with Aminoboronic Acids

Contributor(s): Benjamin List, Saihu Liao
A. Sakakura, T. Ohkubo, R. Yamashita, M. Akakura, K. Ishihara*
Nagoya University, Japan Science and Technology Agency, CREST, Nagoya and Aichi University of Education, Japan
Further Information

Publication History

Publication Date:
18 March 2011 (online)

Significance

An efficient bifunctional Brønsted base assisted aminoboronic acid catalyst (3) has been developed by the authors for the intramolecular dehydrative condensation of dicarboxylic ­acids. With 1 mol% of catalyst 3 and RCN (R = Et, n-Pr, n-Bu) as solvent, various aromatic and aliphatic dicarboxylic acids can be converted into the corresponding anhydrides in high yields (73-100%) under azeotropic reflux conditions. The reaction is suggested to proceed via the formation of monoacyl boronate intermediates. In the proposed activation models A and B, one free amino group would act as a Brønsted base, while the protonated one would act as a proton donor.