Enantioselective acylation of alcohols with fluorinated β-phenyl-β-lactams in the presence of Burkholderia cepacia lipase
作者:Xiang-Guo Li、Maria Lähitie、Mari Päiviö、Liisa T. Kanerva
DOI:10.1016/j.tetasy.2007.06.033
日期:2007.7
the acylation of alcohols with 3,3-difluoro-4-phenylazetidin-2-one rac-1, trans-3-fluoro-4-phenylazetidin-2-one rac-2 and 4-phenylazetidin-2-one rac-3 in the presence of immobilized lipase PS from Burkholderia cepacia in dry tert-butyl methyl ether (TBME). Fluorine activation in the compounds studied was essential in order to split the β-lactam ring with lipase PS. The highly enantioselective ring
本文着重研究醇与3,3-二氟-4-苯基氮杂环丁烷-2-one rac - 1,反式-3-氟-4-苯基氮杂环丁烷-2-one rac - 2和4-苯基氮杂环丁烷2的酰化作用。-酮的外消旋- 3中存在固定的脂肪酶PS从洋葱伯克霍尔德氏菌的无水叔丁基甲基醚(TBME)。为了用脂肪酶PS裂解β-内酰胺环,所研究化合物中的氟活化是必不可少的。rac - 1和rac - 2的高对映选择性开环用甲醇(还研究了1-丁醇)可以制备(R /(3 R,4 R))-β-内酰胺类未反应的对映体和(S /(2 S,3 S))-β-氨基酯为对映体,ee≥99%。在相同条件下,rac - 3完全不起作用。还讨论了酶制剂中水引起竞争性水解的可能性。