Base-Catalyzed Stereospecific Isomerization of Electron-Deficient Allylic Alcohols and Ethers through Ion-Pairing
作者:Samuel Martinez-Erro、Amparo Sanz-Marco、Antonio Bermejo Gómez、Ana Vázquez-Romero、Mårten S. G. Ahlquist、Belén Martín-Matute
DOI:10.1021/jacs.6b08350
日期:2016.10.12
between an allylic anion and the conjugate acid of the base results in efficient transfer of chirality. Through this mechanism, stereochemical information contained in the allylic alcohols is transferred to the ketone products. The stereospecific isomerization is also applicable for the first time to allylic ethers, yielding synthetically valuable enantioenriched (up to 97% ee) enol ethers.
已开发出一种用于烯丙醇和烯丙醚异构化的温和碱催化策略。实验和计算研究表明,当存在碱性添加剂时,不需要过渡金属催化剂。与在碱性条件下使用过渡金属的情况一样,仅由碱催化的异构化也遵循立体定向途径。该反应由限速去质子化引发。在烯丙基阴离子和碱的共轭酸之间形成紧密离子对导致手性的有效转移。通过这种机制,烯丙醇中包含的立体化学信息被转移到酮产品中。立体有择异构化也首次适用于烯丙基醚,