Synfacts 2011(1): 0093-0093  
DOI: 10.1055/s-0030-1259183
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart ˙ New York

Chiral Trisimidazoline Catalyzed Bromolactonization

Contributor(s): Benjamin List, Steffen Müller
K. Murai, T. Matsushita, A. Nakamura, S. Fukushima, M. Shimura, H. Fujioka*
Osaka University, Japan
Further Information

Publication History

Publication Date:
21 December 2010 (online)


The authors report an enantioselective bromolactonization of 5-substituted 5-hexenoic acids, catalyzed by the chiral C 3-symmetric trisimidazoline 1. By using 1,3-dibromo-5,5-di­methylhydantoin (DBDMH) as the Br+ source, a variety of 5-hexenoic acids, preferentially 5-aryl-substituted, were converted into the corresponding δ-lactones in high yields and enantioselectivities. The proposed mode of action involves the formation of a 1:3 complex of 1 and the substrate, at the same time embedding the substrate in a chiral environment and activating the carboxylic acid function. This proposal is supported by mechanistic studies and the utility of the products is underlined by derivatizations of the obtained bromolactones.