Superparamagnetic Fe3O4is shown to act as a very efficient catalyst for the one-pot, three-component synthesis of 5,5-disubstituted hexahydropyrimidines and their spiropiperidines. The catalyst is easily recovered by the use of an external magnet and reused in several reactions without any noticeable loss of activity. The products are obtained in short time and good purity upon separation of the catalyst and evaporation of the volatiles of the reaction mixture.
The following article from the Journal of Applied Polymer Science, “Isolation and chemical structure characterization of enzymatic lignin from Populus deltoides wood,” by Ali Abdulkhani, Alinaghi Karimi, Ahmad Mirshokraie, Yahya Hamzeh, Nathalie Marlin, and Gerard Mortha, published online on 21 May 2010 in Wiley Online Library (wileyonlinelibrary.com), and in Volume 118, pp. 469‐479, has been retracted by agreement between the authors, the journal's editors, and Wiley Periodicals, Inc. The retraction has been agreed due to unacknowledged overlap between Figure 5 in the above paper and Figure 1 in Industrial Crops and Products, Volume 30 (2009), p. 137, as well as inappropriate data manipulation associated with this figure. The publisher acknowledges that co‐authors Nathalie Marlin and Gerard Mortha are not responsible for the issues associated with this article.
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