Lipase-catalyzed enantioselective desymmetrization of prochiral 3,3-bis(hydroxymethyl)oxindoles
作者:Shuji Akai、Toshiaki Tsujino、Tadaatsu Naka、Kouichi Tanimoto、Yasuyuki Kita
DOI:10.1016/s0040-4039(01)01547-7
日期:2001.10
Oxindoles 3b–d (91–98% ee) having a chiral quaternary carbon center at the C-3 position were prepared from readily available oxindoles 5a–c in 50–64% overall yields, in which an enantioselectivedesymmetrization of prochiral 1,3-diols 2b–d using a Candida rugosa lipase (Meito OF) and 1-ethoxyvinyl 2-furoate 1 was employed as the key step.
羟吲哚3b的- d(91-98%ee)的具有在C-3位手性季碳中心从容易得到的羟吲哚制备了图5a - Ç在50-64%总产率,其中前手性的1,3-对映选择性desymmetrization采用皱纹念珠菌脂肪酶(Meito OF)和2-糠酸1-乙氧基乙烯基酯1制成的2- b - d二醇是关键步骤。
Enantiodivergent Preparation of Optically Active Oxindoles Having a Stereogenic Quaternary Carbon Center at the C3 Position via the Lipase-Catalyzed Desymmetrization Protocol: Effective Use of 2-Furoates for Either Enzymatic Esterification or Hydrolysis
作者:Shuji Akai、Toshiaki Tsujino、Emi Akiyama、Kouichi Tanimoto、Tadaatsu Naka、Yasuyuki Kita
DOI:10.1021/jo035749h
日期:2004.4.1
the C3 position and a different N-protective group, were readily prepared by the lipase-catalyzed desymmetrization protocol. Thus, the transesterification of the prochiral diols 3a−h with 1-ethoxyvinyl 2-furoate 5 was catalyzed by Candida rugosa lipase to give (R)-(+)-2a−h (68−99% ee), in which the use of a mixed solvent, iPr2O (diisopropyl ether)−THF, was crucial. The same lipase also effected the