Chemoenzymatic synthesis of enantiopure 1-phenyl-2-haloethanols and their esters
摘要:
Several secondary haloalcohols have been resolved by esterification catalyzed by lipases A and B from Candida antarctica (CALA and CALB, respectively). Immobilized CALB (Novozym 435) gave better selectivities and faster reaction rates than CALA (Novozyme 735) with all of the substrates. Vinyl butanoate was the favoured acyl donor compared to vinyl acetate due to remarkably faster reactions. The alcohols (R)-2a, (R)-2c and the butanoates (S)-3a-c have been isolated with 98-99% enantiomeric excess (ee) in good yields.
DMSO-triggered enhancement of enantioselectivity in Novozyme[435]-catalyzed transesterification of chiral 1-phenylethanols
作者:Amrit Goswami、Jonali Goswami
DOI:10.1016/j.tetlet.2005.03.147
日期:2005.6
Dimethyl sulfoxide as cosolvent enhances the enantioselectivity of resolved products up to 100% in the Novozyme[435]-catalyzed transesterification of chiral 1-phenylethanols but not 1-phenyl-2-haloethanols in THF. The reaction does not proceed in lipophilic and water-miscible polar solvents.
One-pot lipase-catalyzed synthesis of enantiopure secondary alcohols from carbonyl compounds: a new protocol for lipase-mediated resolution
作者:Ahmed Kamal、Mahendra Sandbhor、K.Venkata Ramana
DOI:10.1016/s0957-4166(02)00170-2
日期:2002.5
Reduction of acetophenones with sodium borohydride in the presence of neutral alumina in hexane followed by enantioselective acylation catalyzed by Pseudomonas cepacia lipase has been achieved in one-pot. Further, immobilized lipase offered a high degree of selectivity with spontaneity. (C) 2002 Elsevier Science Ltd. All rights reserved.
Chemoenzymatic synthesis of enantiopure 1-phenyl-2-haloethanols and their esters
作者:Sina Maria Lystvet、Bård Helge Hoff、Thorleif Anthonsen、Elisabeth Egholm Jacobsen
DOI:10.3109/10242422.2010.501406
日期:2010.7
Several secondary haloalcohols have been resolved by esterification catalyzed by lipases A and B from Candida antarctica (CALA and CALB, respectively). Immobilized CALB (Novozym 435) gave better selectivities and faster reaction rates than CALA (Novozyme 735) with all of the substrates. Vinyl butanoate was the favoured acyl donor compared to vinyl acetate due to remarkably faster reactions. The alcohols (R)-2a, (R)-2c and the butanoates (S)-3a-c have been isolated with 98-99% enantiomeric excess (ee) in good yields.