Helical peptide foldamer catalyzed Michael addition reactions of nitroalkane or dialkyl malonate to α,β-unsaturated ketones are reported along with the mechanistic considerations of the enantio-induction. A wide variety of α,β-unsaturated ketones, including β-aryl, β-alkyl enones, and cyclic enones, were found to be catalyzed by the helical peptide to give Michael adducts with high enantioselectivities
Enantioselective Organocatalytic Michael Addition of Aliphatic Ketones to Nitrodienes
作者:Tianxiong He、Xin-Yan Wu
DOI:10.1080/00397911.2010.529227
日期:2012.3.1
Abstract A highly enantioselectiveMichaeladdition of aliphatic ketones to nitrodienes has been achieved that is catalyzed by readily available chiral thioureas derived from (1R,2R)-diphenylethane-1,2-diamine. Treatment of ketones with nitrodienes in the presence of 10 mol% thiourea 1a and 10 mol% benzoic acid in toluene provided the desired Michael adducts with excellent enantioselectivities (up to 99%
Highly Enantioselective Michael Addition of Aromatic Ketones to Nitrodienes and the Application to the Synthesis of Chiral γ-Aminobutyric Acid
作者:Xin-Yan Wu、Xing-Tao Guo、Feng Sha
DOI:10.1055/s-0036-1588604
日期:——
oic acid. A highly enantioselective Michaeladdition of aromatic ketones to α,β,γ,δ-unsaturated nitro compounds is described. In the presence of a chiral primary amine-thiourea based on dehydroabietic amine, γ-nitro ketones were obtained in excellent enantioselectivities (up to 95% ee) with up to 95% yield. In addition, this methodology has been successfully applied in the asymmetric synthesis of chiral