All-carbon quaternary stereogenic centers by enantioselective Cu-catalyzed conjugate additions promoted by a chiral N-heterocyclic carbene

Abstract

(Chemical Equation Presented) Necessity is the mother of invention: When the available catalysts do not cut it, a new one has to be developed. A chiral N-heterocyclic carbene (NHC) is used in the first catalytic asymmetric conjugate addition of alkyl- and arylzinc reagents to γ-keto esters (see scheme). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.