Novel Bifunctional Chiral Urea and Thiourea Derivatives as Organocatalysts: Enantioselective Nitro‐Michael Reaction of Malonates and Diketones

Novel chiral ureas and thioureas derived form natural α-amino acids have been prepared and tested as bifunctional organocatalysts in enantioselective nitro-Michael additions (see scheme). The reactions occurred with excellent chemical yields and up to 99 % ee. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2111/2008/z800633_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.