Hybrid Diamines Derived from 1,1′-Binaphthyl-2,2′-diamine and α-Amino Acids as Organocatalysts for 1,3-Dipolar Cycloaddition of Aromatic Nitrones to (E)-Crotonaldehyde
2'-diamine and various α-amino acids were prepared using a convenient procedure. They were tested as organocatalysts for 1,3-dipolarcycloaddition of aromatic nitrones to (E)-crotonaldehyde. The L-pbenylalanine-based catalyst 10 afforded superior results, with good endo diastereoselectivity, and enantioselectivity of up to 95% ee.
使用方便的程序制备 1,1'-联萘-2,2'-二胺和各种 α-氨基酸的同手性衍生物。将它们作为有机催化剂进行测试,用于芳族硝酮与 (E)-巴豆醛的 1,3-偶极环加成反应。L-苯丙氨酸基催化剂 10 提供了优异的结果,具有良好的内非对映选择性和高达 95% ee 的对映选择性。
A new organocatalyst for 1,3-dipolar cycloadditions of nitrones to α,β-unsaturated aldehydes
作者:San San Chow、Marta Nevalainen、Catherine A. Evans、Charles W. Johannes
DOI:10.1016/j.tetlet.2006.11.029
日期:2007.1
The triflate salt resulting from the treatment of diphenyl-S-prolinol with trimethylsilyl triflate, catalyzes the addition of nitrones to α,β-unsaturatedaldehydes to provide isoxazolidines in high yields and excellent diastereo- and enantioselectivities.
AbstractA 1,3‐dipolar azide–alkyne cycloaddition has been used to prepare a magnetic nanoparticle immobilized MacMillan catalyst that catalyzes the enantioselective 1,3‐dipolar cycloaddition between nitrones and α,β‐unsaturated aldehydes. The catalyst can be recovered and recycled for five consecutive runs without any significant loss in yields and diastereo‐ and enantioselectivities of the isoxazolidines.magnified image