Organocatalytic Oxidative Cleavage of C-C Double and Triple Bonds
K. Miyamoto, Y. Sei, K. Yamaguchi, M. Ochiai*
University of Tokushima and Tokushima Bunri University, Sanuki, Japan
23. März 2009 (online)
The authors present further developments of their recently reported oxidative cleavage of C-C double bonds using aryl-λ³-iodanes as the catalytically active species (J. Am. Chem. Soc. 2007, 129, 2772). In the present work iodo-mesitylene (1) was used as organocatalyst for the cleavage of C-C double and triple bonds in the presence of aqueous HBF4 and MCPBA as the stoichiometric oxidant. The proposed mechanism involves oxidation of the olefin to the corresponding 1,2-diol 2, presumably forming a dialkoxy-λ³-iodane 3 with the dihydroxy-λ³-iodane 4, which is generated in situ from the catalyst 1 and MCPBA in the presence of aqueous HBF4. After the cleavage of 3 the resulting carbonyl compound is finally oxidized to the corresponding carboxylic acid.