Carbonylation of alkyl sulfonates catalyzed by cobalt complexes
作者:Hisao Urata、Daisuke Goto、Takamasa Fuchikami
DOI:10.1016/0040-4039(91)80697-5
日期:1991.6
Alkylsulfonates (R1-OSO2R2) react with carbon monoxide and alcohol (R3-OH) in the presence of catalytic amounts of Co complex and Nal to afford the corresponding esters (R1-COOR3) in moderate to good yields.
Transformation of racemic ethyl 3-hydroxybutanoate into the (R)-enantiomer exploiting lipase catalysis and inversion of configuration
作者:Mihaela C. Turcu、Eero Kiljunen、Liisa T. Kanerva
DOI:10.1016/j.tetasy.2007.06.030
日期:2007.7
Racemic ethyl 3-hydroxybutanoate rac-1 was transformed into ethyl (R)-acetoxybutanoate (ee = 92%) with 85-90% chemical yields using enantioselective acylation with isopropenyl acetate in the presence of Candida antarctica lipase B (CAL-B, Novozym 435) under solvent-free conditions, followed by mesylation of the unreacted (S)-alcohol in the reaction mixture and inversion of configuration with cesium acetate in DMF in one pot. When the (R)-acetoxybutanoate was subjected to alcoholysis with ethanol and CAL-B, enantiopure (R)-1 (ee > 99%) was produced. (c) 2007 Elsevier Ltd. All rights reserved.