Catalytic Epoxidation of Enones Mediated by Zinc Alkylperoxide/tert-BuOOH Systems
a Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
b Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
c University of Warsaw, Faculty of Chemistry, Pasteura 1, 02-093 Warsaw, Poland
d Institute for Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstr. 15, Geb. 30.45, 76131 Karlsruhe, Germany
Received 13 Aug 2013, Accepted 17 Sep 2013
First published online 18 Sep 2013
The epoxidation of enones by zinc alkylperoxides is a challenging task receiving considerable attention in contemporary research; however, until now no well-defined zinc alkylperoxide based systems have been described. Here, a new catalytic method of epoxidation of enones in the presence of zinc alkylperoxides supported by N,N-bidentate ligands and tert-butyl hydroperoxide is reported. A new dimeric zinc alkylperoxide complex supported by an aminotroponiminate ligand is also presented. The studied catalytic systems show high activity in the epoxidation of trans-chalcone, and in the case of a chiral catalyst with the (S,S)-N,N′-bis(1-phenylethyl)aminotroponiminate ligand a moderate enantioselectivity was achieved.