Modular Spiro Bidentate Nitrogen Ligands - Synthesis, Resolution and Application in Asymmetric Catalysis
作者:Xavier Sala、Eduardo J. García Suárez、Zoraida Freixa、Jordi Benet-Buchholz、Piet W. N. M. van Leeuwen
DOI:10.1002/ejoc.200800913
日期:2008.12
imino derivatives [(+)-7/(–)-7] were obtained in both enantiomeric forms. A new SPAN derivative incorporating aldehyde groups at the 8,8′ positions of the spirobi(chroman) unit [(+)-9/(–)-9] has been synthesized with the aim to extend the ligand library by means of Schiff base chemistry. The derivatization of the isolated enantiomers of 9 obtained by diastereomer resolution gave derivatives containing