A New Class of Substituted Aryl Bis(oxazoline) Ligands for Highly Enantioselective Copper-Catalyzed Asymmetric Aldol Addition of Dienolsilane to Pyruvate and Glyoxylate Esters
作者:Julie Cong-Dung Le、Brian L. Pagenkopf
DOI:10.1021/ol048179w
日期:2004.10.1
[reaction: see text] A new class of bis(oxazoline) ligands are introduced that feature o-alkoxyaryl substituents and provide the highest enantioselectivities yet reported for the copper-catalyzedasymmetric dienosilane aldol addition to pyruvate and glyoxylate esters. Enantioselectivities up to 98% ee (before recrystallization) and isolated yields up to 91% were observed. Additionally, chloride counterions