Chiral linker. Part 2: Synthesis and evaluation of a novel, reusable solid-supported open chain chiral auxiliary derived from m-hydrobenzoin for the diastereoselective reduction of α-keto esters
摘要:
Three novel m-hydrobenzoin derived chiral hydrobenzoin mono-alkyl ethers were synthesized and evaluated as open chain chiral auxiliaries in the L-selectride(R)/ZnCl2 mediated stereoselective reduction of their corresponding phenyl glyoxylates, resulting in des of up to 91%. The optimized auxiliary structure was immobilized on commercially available Wang-resin by using the ether substituent as a sublinking unit and applied as a reusable solid-supported chiral auxiliary in the same type of reaction with only little loss of stereofacial selectivity. (c) 2005 Elsevier Ltd. All rights reserved.
Chiral linker. Part 2: Synthesis and evaluation of a novel, reusable solid-supported open chain chiral auxiliary derived from m-hydrobenzoin for the diastereoselective reduction of α-keto esters
摘要:
Three novel m-hydrobenzoin derived chiral hydrobenzoin mono-alkyl ethers were synthesized and evaluated as open chain chiral auxiliaries in the L-selectride(R)/ZnCl2 mediated stereoselective reduction of their corresponding phenyl glyoxylates, resulting in des of up to 91%. The optimized auxiliary structure was immobilized on commercially available Wang-resin by using the ether substituent as a sublinking unit and applied as a reusable solid-supported chiral auxiliary in the same type of reaction with only little loss of stereofacial selectivity. (c) 2005 Elsevier Ltd. All rights reserved.
Application of meso-hydrobenzoin-derived chiral auxiliaries for the stereoselective synthesis of highly substituted pyrrolidines by 1,3-dipolar cycloaddition of azomethine ylides
作者:Katharina Bica、Peter Gaertner
DOI:10.1016/j.tetasy.2010.04.010
日期:2010.4
The metal-catalyzed stereoselective 1,3-dipolar cycloaddition of azomethine ylides and acrylates using recyclable meso-hydrobenzoin-derived chiral auxiliaries is described. Cleavage of the auxiliary leads to highly substituted pyrrolidines in up to 87% enantiomeric excess. (C) 2010 Elsevier Ltd. All rights reserved.