Synfacts 2009(2): 0212-0212  
DOI: 10.1055/s-0028-1087591
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart ˙ New York

Primary-Secondary Diamine Catalysts for Malonate Additions to Enones

Contributor(s): Benjamin List, Corinna Reisinger
Y.-Q. Yang, G. Zhao*
University of Science and Technology of China, Hefei and Shanghai Institute of Organic Chemistry, P. R. of China
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Publication History

Publication Date:
22 January 2009 (online)


This work describes the highly enantioselective Michael addition of dibenzyl ­malonate 2 to enones 1 in the presence of a catalytic amount (20 mol%) of the TFA salt of the novel primary-secondary diamine 3. A broad range of benzylideneacetone derivatives, irrespective of their electronic nature, chalcone, an aliphatic enone, and cyclohexenone were suitable substrates yielding the corresponding products 4 in good to excellent yields (66-99%) and enantiomeric ratios of up to >99.5:0.5. Notably, in contrast to previous studies on the same reaction, the use of two equivalents of the malonate component was sufficient. The authors’ working hypo­thesis invokes a bifunctional iminium mechanism with the enone being activated as iminium ion (see Scheme, 5).