Download PDF
Synfacts 2011(1): 0092-0092  
DOI: 10.1055/s-0030-1259181
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart ˙ New York

Cinchona Amino-Thiocarbamate Catalyzed Bromolactonization

Contributor(s): Benjamin List, Steffen Müller
L. Zhou, C. K. Tan, X. Jiang, F. Chen, Y.-Y. Yeung*
National University of Singapore, Singapore
Further Information

Publication History

Publication Date:
21 December 2010 (online)

    Permissions and Reprints

Significance

A cinchonine-derived thiocarba­mate is reported to efficiently catalyze the bromolactonization of 4-substituted 4-pentenoic acids to give the corresponding γ-lactones in high yields and good enantioselectivities. Catalyst 1 is presumed to act as a bifunctional catalyst, simultaneously activating NBS with the Lewis-basic ­thiocarbamate and the carboxylic acid with the Brønsted-basic tertiary amine. The utility of the products is demonstrated and initial mechanistic studies, supporting the suggested bifunctional mechanism, are provided.