AbstractThe incorporation of fluorine atoms in organics improves their bioactivity and lipophilicity. Catalytic functionalization of gem‐difluorodienes represents one of the most straightforward approaches to access fluorinated alkenes. In contrast to the regular 1,3‐dienes that undergo diverse asymmetric di/hydrofunctionalizations, the regio‐ and enantioselective oxyamination of gem‐difluorodienes remains untouched. Herein, we report asymmetric 1,4‐oxyamination of gem‐difluorodiene by chiral rhodium‐catalyzed three‐component coupling with readily available carboxylic acid and dioxazolone, affording gem‐difluorinated 1,4‐amino alcohol derivatives. Our asymmetric protocol exhibits high 1,4‐regio‐ and enantioselectivity with utility in the late‐stage modification of pharmaceuticals and natural products. Stoichiometric experiments provide evidences for the π‐allylrhodium pathway. Related oxyamination was also realized when trifluoroethanol was used as an oxygen nucleophile.
摘要在有机物中加入
氟原子可提高其
生物活性和亲油性。催化二
氟二烯的官能化是获得
氟化烯的最直接方法之一。与常规的 1,3-二烯进行多种不对称的二/氢官能化相比,宝石-二
氟二烯的区域和对映选择性氧合反应仍未涉及。在此,我们报告了通过手性
铑催化的三组分偶联与现成的
羧酸和二
噁唑酮对宝石-二
氟二烯进行不对称 1,4- 氧化反应,从而得到宝石-二
氟化 1,4-
氨基醇衍
生物的情况。我们的不对称方案具有很高的 1,4-对映和对映选择性,可用于药物和天然产品的后期改性。计量学实验为π-烯丙基
铑途径提供了证据。当使用
三氟乙醇作为氧亲核体时,还实现了相关的氧合反应。