Denmark Scott E, Bui Tommy
Department of Chemistry, Roger Adams Laboratory, University of Illinois, Urbana, IL 61801, USA.
Proc Natl Acad Sci U S A. 2004 Apr 13;101(15):5439-44. doi: 10.1073/pnas.0307212101. Epub 2004 Apr 5.
Catalytic, enantioselective, directed cross-aldol reactions of aldehydes are described. The addition of isobutyraldehyde trichlorosilyl enolate 2 to various aldehydes in the presence of 10 mol % bisphosphoramide 4 provides aldol products in high yields with moderate to good enantioselectivities. The reaction works well with a wide range of aromatic, olefinic, and aliphatic aldehydes. Enantioselectivities are highly dependent on the electronic nature of the aldehyde substituent. Hammett studies reveal that enantioselectivity increases as aldehydes become either more electron rich or more electron poor.
描述了醛的催化、对映选择性、定向交叉羟醛反应。在10 mol%双磷酰胺4存在下，将异丁醛三氯硅烯醇化物2添加到各种醛中，可高产率地提供羟醛产物，对映选择性中等至良好。该反应对多种芳香族、烯烃和脂肪族醛都能很好地起作用。对映选择性高度依赖于醛取代基的电子性质。哈米特研究表明，随着醛变得电子更丰富或电子更缺乏，对映选择性增加。
