Title of article :
A Poly(ethylene glycol) Supported Chiral Auxiliary for Asymmetric Michael Reactions
Author/Authors :
Baro، Angelika نويسنده , , Kreidler، Burkard نويسنده , , Christoffers، Jens نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2005
Abstract :
The synthesis of a novel polymer-bound L-valine derived auxiliary 10 is reported. Its synthetic use is demonstrated in asymmetric copper(II)catalyzed Michael reactions of cyclic (beta)-oxo esters 12 with methyl vinyl ketone (2), yielding the corresponding addition products 3 with quaternary stereocenter in selectivities up to 99% ee. The immobilized auxiliary 10 can be recovered by simple precipitation from diethyl ether.
Keywords :
chiral auxiliary , Michael addition , Immobilization , soluble polymer , quaternary stereocenters
