Large-Scale Synthesis of Singh’s Catalyst in a One-Pot Procedure Starting from Proline
作者:Albrecht Berkessel、Wacharee Harnying、Nongnaphat Duangdee、Jörg-M. Neudörfl、Harald Gröger
DOI:10.1021/op200283q
日期:2012.1.20
A practical one-pot procedure for the preparation of Singh's catalyst from either L-/D-proline or Boc-proline is described. The coupling partner, a chiral amino alcohol, can be prepared and used directly without purification from the corresponding amino acid ester. Moreover, a procedure for tert-butoxycarbonyl (Boc) group removal using concentrated HCl in MeOH-DCM was developed and utilized for the multigram-scale synthesis of Singh's catalyst.