Chemoenzymatic approach to enantiopure piperidine-based β-amino esters in organic solvents
作者:Arto Liljeblad、Hanna-Maija Kavenius、Petri Tähtinen、Liisa T. Kanerva
DOI:10.1016/j.tetasy.2007.01.027
日期:2007.2
This research concentrates on the enantioselectivities of lipase-catalysed reactions with methyl esters of 2-piperidylacetic acid and 3-piperidinecarboxylic acid derivatives. N-Acetylated 2-piperidylacetic acid methyl ester displayed good enantioselectivity (E = 66) in a 1:1 mixture of diisopropyl ether and butyl butanoate in the presence of lipase PS-C IT from Burkholderia cepacia. The reaction is known as interesterification with butyl butanoate rather than alcoholysis with the butanol, because butyl butanoate has to be first hydrolysed or go through alcoholysis with MeOH in order to release butanol. Other N-protective groups (Boc, Ns, Fmoc and Bzn) gave excellent en anti oselectivity (E > 200) under the same conditions, and a gram-scale resolution was performed with N-Boc-2-piperidylacetic acid methyl ester. Reaction with a 3-piperidylcarboxylic acid derivative took place with disappointingly low enantioselectivity (E = 4), with Candida antarctica lipase B being the best of the lipases screened. (c) 2007 Elsevier Ltd. All rights reserved.