Catalytic Enantioselective Michael Additions to Unsaturated Ester Derivatives Using Chiral Copper(II) Lewis Acid Complexes
作者:David A. Evans、Michael C. Willis、Jeffrey N. Johnston
DOI:10.1021/ol9901570
日期:1999.9.1
[formula: see text] Chiral Cu(II) bisoxazoline (box) Lewisacids have been developed as catalysts of the Michael addition of enolsilanes to unsaturated ester derivatives. While enantioselection is stereoregular, the sense of diastereoselection is directly related to thioester enolsilane geometry: (E) enolsilanes give anti adducts and (Z) enolsilanes afford syn adducts. The size of the enolsilane alkylthio