A new one‐potsynthesis of 9‐(pyridin‐2‐yl)‐9H‐carbazoles through the simultaneous CH activation and palladium(II)‐catalyzed cross‐coupling of N‐phenylpyridin‐2‐amines with potassium aryltrifluoroborates is presented. Silver acetate and 1,4‐dioxane proved to be the best oxidant and solvent, respectively. The product yields fluctuated from modest to excellent and the reaction showed sufficient functional
通过同时的CH活化和钯(II)催化的N-苯基吡啶-2-胺与芳基三氟硼酸钾的交叉偶联,新的一锅合成9-(吡啶-2-基)-9 H-咔唑的方法是提出了。醋酸银和1,4-二恶烷分别被证明是最好的氧化剂和溶剂。产物收率从适中波动至优异,反应显示出足够的官能团耐受性。对苯醌是催化过程中金属转移和还原消除步骤的重要配体。第一和第二次CH活化/ C的动力学同位素效应(k H / k D)。 C或C ñ形成步骤测量为分别2.14和1.18,。最后,基于所有实验证据提出了合理的催化机理。
Synthesis of 2-Formyl Carbazoles via Tandem Reaction of Indolyl Nitrones with 2-Methylidene Cyclic Carbonate
作者:Sujin Min、Taeeun Kim、Taejoo Jeong、Junhyeok Yang、Yebin Oh、Kyeongwon Moon、Amitava Rakshit、In Su Kim
DOI:10.1021/acs.orglett.3c01336
日期:2023.6.16
The synthesis of functionalized carbazoles as privileged nitrogen heterocycles has emerged as a central topic in drug discovery and material science. We herein disclose the rhodium(III)-catalyzed cross-coupling reaction between indolyl nitrones and 2-methylidene cyclic carbonate as an allylating surrogate, resulting in the formation of C2-formylated carbazolesvia tandem C–H allylation, [3 + 2] cycloaddition