Chemoenzymatic preparation of fluorine-substituted β-lactam enantiomers exploiting Burkholderia cepacia lipase
摘要:
Both enantiomers of fluorinated and non-fluorinated 4-phenyl-2-azetidinones are prepared in high enantiopurities (ee 99%) by a chemoenzymatic method, using a double resolution technique to N-hydroxymethylated beta-lactams in the presence of Burkholderia cepacia lipase as the source of enantiopurity. N-Deprotections yield the beta-lactam enantiomers from the corresponding hydroxymethylated counterparts using KMnO4 in a mixture of acetone and water. (c) 2007 Elsevier Ltd. All rights reserved.
Burkholderia cepacia lipase and activated β-lactams in β-dipeptide and β-amino amide synthesis
作者:Xiang-Guo Li、Maria Lähitie、Liisa T. Kanerva
DOI:10.1016/j.tetasy.2008.07.017
日期:2008.8
The work describes fluorine-activated and N-Boc-activated beta-lactams as acyl donors to N-nucleophiles in the presence of Burkholderia cepacia lipase (lipase PS-D). Fluorine activation at the beta-lactam ring causes the ring to open in high enantioselectivity and allows the preparation of beta-dipeptides and beta-amino amides. in the case of N-Boc-activation, the chemical ring opening is significant. beta-Dipeptide formation can then be considerably enhanced by the presence of lipase PS-D and/or by temperature. (C) 2008 Elsevier Ltd. All rights reserved.