The catalytic activity of a simple aminoalcohol that contains a bulky super silyl group [i.e., tris(trimethylsilyl)silyl (TTMSS)] bonded to the oxygen atom at the γ-position along with a primary amine moiety was examined in the enantioselective1,3-dipolarcycloaddition of nitrones to α,β-unsaturatedaldehydes. The organocatalyst successfully provided optically active isoxazolidines in good chemical
Enantioselective 1,3-dipolar cycloadditions of nitrones with unsaturated aldehydes promoted by a recyclable tetraarylphosphonium supported imidazolidinone catalyst
作者:Xin Nie、Cuifen Lu、Zuxing Chen、Guichun Yang、Junqi Nie
DOI:10.1016/j.molcata.2014.06.015
日期:2014.11
The tetraarylphosphonium supported chiral imidazolidinone catalyzes the enantioselective1,3-dipolarcycloadditions of nitrones and α,β-unsaturatedaldehydes to provide isoxazolidine aldehydes in good yields with excellent diastereo- and enantioselectivities. Most importantly, the tetraarylphosphonium supported imidazolidinone catalyst can be readily recovered and recycled for further transformations
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 Magnetoclick Imidazolidinone Nanocatalyst for Asymmetric 1,3‐Dipolar Cycloadditions
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