Gilbert Bradley B, Eey Stanley T-C, Ryabchuk Pavel, Garry Olivia, Denmark Scott E
Department of Chemistry, University of Illinois, 600 S. Mathews Ave. Urbana, IL 61801, USA.
Tetrahedron. 2019 Jul 2;75(31):4086-4098. doi: 10.1016/j.tet.2019.05.054. Epub 2019 Jun 1.
The enantioselective dichlorination of alkenes is a continuing challenge in organic synthesis owing to the limitations of selective and independent antarafacial delivery of both electrophilic chlorenium and nucleophilic chloride to an olefin. Development of a general method for the enantioselective dichlorination of isolated alkenes would allow access to a wide variety of polyhalogenated natural products. Accordingly, the enantioselective dichlorination of alkenes catalyzed by electrophilic organoselenium reagents has been developed to address these limitations. The evaluation of twenty-three diselenides as precatalysts for enantioselective dichlorination is described, with a maximum e.r. of 76:24 Additionally, mechanistic studies suggest an unexpected Dynamic Kinetic Asymmetric Transformation (DyKAT) process may be operative.
由于在向烯烃选择性且独立地进行亲电氯鎓和亲核氯的异面传递方面存在局限性，烯烃的对映选择性二氯化反应一直是有机合成中的一项挑战。开发一种用于孤立烯烃对映选择性二氯化的通用方法将有助于获得多种多卤代天然产物。因此，已开发出由亲电有机硒试剂催化的烯烃对映选择性二氯化反应来克服这些局限性。本文描述了对23种二硒醚作为对映选择性二氯化反应预催化剂的评估，最大对映体比率为76:24。此外，机理研究表明可能存在一种意想不到的动态动力学不对称转化（DyKAT）过程。
