Asymmetric Chemoenzymatic Synthesis of Ramatroban Using Lipases and Oxidoreductases
作者:Eduardo Busto、Vicente Gotor-Fernández、Vicente Gotor
DOI:10.1021/jo300552v
日期:2012.5.18
9-dihydro-1H-carbazol-3(2H)-one provided an alternative access to the same enantiopure alcohol previously obtained through lipase-catalyzed resolution, a useful synthetic building block in the synthesis of ramatroban. Inversion of the absolute configuration of (S)-2,3,4,9-tetrahydro-1H-carbazol-3-ol has been identified as a key point in the synthetic route, optimizing this process to avoid racemization of the
首次开发了用于制备对映纯(R)-ramatroban的化学酶促不对称路线。脂肪酶和氧化还原酶的作用已被独立研究,并且被发现是在非常温和的反应条件下生产足够的手性中间体的优秀生物催化剂。CAL-B有效地催化了(±)-2,3,4,9-四氢-1 H-咔唑-3-醇的拆分,该拆分被高度立体控制。另一方面,ADH-A介导的4,9-dihydro-1 H -carbazol-3(2 H)-提供了另一种途径获得相同的对映纯醇,该对映体先前通过脂肪酶催化的拆分获得,这是合成ramatroban的有用合成基础。(S)-2,3,4,9-四氢-1 H-咔唑-3-醇的绝对构型反转已被确定为合成路线中的关键点,优化了该过程以避免叠氮化物中间体的消旋化,通过形成相应的胺和方便地官能化环外和吲哚氮原子,最终以对映纯形式生成(R)-雷马曲班。