A Chiral Ag-Based Catalyst for Practical, Efficient, and Highly Enantioselective Additions of Enolsilanes to α-Ketoesters
作者:Laura C. Akullian、Marc L. Snapper、Amir H. Hoveyda
DOI:10.1021/ja061166o
日期:2006.5.1
A Ag-based chiral catalyst promotes efficient and highly enantioselective aldol additions of ketone-derived enolsilanes to alpha-ketoesters in the presence of a readily available amino acid-based ligand and commercially available AgF2. alpha-Ketoester substrates may bear alkyl, alkenyl, and aryl substituents; reactions proceed to >98% conversion to afford the desired tertiary alcohols in 61->98% isolated
在容易获得的基于氨基酸的配体和市售的 AgF2 存在下,基于 Ag 的手性催化剂促进了酮衍生的烯醇硅烷向 α-酮酯的高效和高度对映选择性羟醛加成。α-酮酯底物可带有烷基、烯基和芳基取代基;反应进行到 >98% 的转化率,以 61->98% 的分离产率和 60-96% 的 ee 得到所需的叔醇。与之前报道的方法相比,在空间要求严格的底物上观察到了最高的对映选择性,并且反应可以在未蒸馏的溶剂中、在空气中使用低至 1 mol% 的催化剂进行。