Asymmetric Organocatalysis with Novel Chiral Thiourea Derivatives: Bifunctional Catalysts for the Strecker and Nitro-Michael Reactions
作者:Svetlana B. Tsogoeva、Denis A. Yalalov、Martin J. Hateley、Christoph Weckbecker、Klaus Huthmacher
DOI:10.1002/ejoc.200500420
日期:2005.12
both a thiourea moiety and an imidazole group on a chiral scaffold were synthesized and applied to the Strecker synthesis and nitro-Michael reaction. The addition of acetone to nitroolefins in the presence of these novel bifunctional organocatalysts gave enantioselectivities (up to 87 % ee) that are superior to those generated by the proline and/or homo-proline tetrazole catalysts described in the literature