Allyl 4-Chlorophenyl Sulfone as a Versatile 1,1-Synthon for Sequential α-Alkylation/Cobalt-Catalyzed Allylic Substitution
作者:Masahiro Kojima、Shigeki Matsunaga、Tomoyuki Sekino、Shunta Sato、Kazuki Kuwabara、Koji Takizawa、Tatsuhiko Yoshino
DOI:10.1055/s-0040-1707524
日期:2020.7
rare 1,1-dipole synthons, allyl sulfones are rarely used in target-oriented syntheses, likely due to the lack of a general catalytic method for their branch-selective allylic substitution. Herein, we identified allyl 4-chlorophenyl sulfone as a versatile linchpin for both base-mediated α-derivatization and subsequent cobalt-catalyzed allylic substitution. The sequential transformations allow for highly
尽管烯丙基砜具有罕见的1,1-偶极合成子的独特潜力,但很少用于目标导向的合成中,这可能是由于缺乏用于支链选择性烯丙基取代的通用催化方法。在这里,我们确定了烯丙基4-氯苯基砜作为通用介导的碱介导的α-衍生化和随后的钴催化的烯丙基取代。连续转化允许高度区域选择性地获得具有多种脂族侧链的支链烯丙基取代产物。与传统的金属催化方案相比,光氧化还原使能的钴催化对于实现高产率和区域选择性的脱磺酰基取代是必不可少的,而传统的金属催化方案在相应的转化中导致了较差的结果。