Akullian Laura C, Snapper Marc L, Hoveyda Amir H
Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
J Am Chem Soc. 2006 May 24;128(20):6532-3. doi: 10.1021/ja061166o.
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 yield and 60-96% ee. In contrast to previously reported approaches, highest enantioselectivities are observed with sterically demanding substrates, and reactions can be carried out in undistilled solvent, in air with as little as 1 mol % catalyst.
一种基于银的手性催化剂，在一种易于获得的氨基酸基配体和市售的AgF₂存在下，能促进酮衍生的烯醇硅烷与α-酮酯的高效且高度对映选择性的羟醛加成反应。α-酮酯底物可以带有烷基、烯基和芳基取代基；反应转化率>98%，以61%->98%的分离产率和60%-96%的对映体过量（ee）得到所需的叔醇。与先前报道的方法相反，对于空间位阻较大的底物观察到最高的对映选择性，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。
