High Performance of a Chiral Diene-Rhodium Catalyst for the Asymmetric 1,4-Addition of Arylboroxines to α,β-Unsaturated Ketones
Fu-Xue Chen, Asato Kina and Tamio Hayashi*
*Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan, Email: thayashikuchem.kyoto-u.ac.jp
F.-X. Chen, A. Kina, T. Hayashi, Org. Lett., 2006, 8, 341-344.
DOI: 10.1021/ol052756e
Abstract
A rhodium complex coordinated with (S,S)-2,5-dibenzylbicyclo[2.2.2]octa-2,5-diene (Bn-bod*) showed high catalytic activity and high enantioselectivity in the asymmetric 1,4-addition of arylboroxines to α,β-unsaturated ketones. It is suggested, that phenylboronic acid contains a small amount of a contaminant which deactivates the catalyst. This impurity was removed during the preparation and purification of the boroxines.
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K. Okamoto, T. Hayashi, V. H. Rawal, Org. Lett., 2008, 10, 4387-4389.
T. Hayashi, K. Ueyama, N. Tokunaga, K. Yoshida, J. Am. Chem. Soc., 2003, 125, 11508-11509.
Key Words
ID: J54-Y2006-300