Lanthanide-catalyzed endo- and enantioselective 1,3-dipolar cycloaddition reactions of nitrones with alkenes
作者:Ana I. Sanchez-Blanco、Kurt V. Gothelf、Karl Anker Jørgensen
DOI:10.1016/s0040-4039(97)10048-x
日期:1997.11
be dependent on the amount and type of molecular sieves added. The application of different chiral ligands in 1,3-dipolarcycloaddition reactions of a series of alkenes with nitrones catalyzed by Yb(OTf)3 or Sc(OTf)3 has been studied and it was found that high endo-selectivities and an ee's of up to 73% could be obtained by the use of Yb(OTf)3 and 2,6-bis[4(S)-isopropyl-2-oxazolidin-2-yl]pyridine (PyBOX)