Asymmetric Conjugate Addition of Malonate Esters to α,β-Unsaturated<i>N</i>-Sulfonyl Imines: An Expeditious Route to Chiral δ-Aminoesters and Piperidones
作者:Miguel Espinosa、Gonzalo Blay、Luz Cardona、José R. Pedro
DOI:10.1002/chem.201302687
日期:2013.10.25
The asymmetric conjugate addition of malonate esters to α,β‐unsaturated N‐sulfonyl imines is catalyzed by PyBOX/La(OTf)3 complexes in the presence of 4 Å MS. The reaction gives the corresponding E enamines bearing a stereogenic center at the allylic position with good yields and enantiomeric ratios up to 97:3. This reaction provides a synthetic entry to chiral δ‐aminoesters and piperidones.