College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China.
Chemistry. 2020 May 26;26(30):6805-6811. doi: 10.1002/chem.201905855. Epub 2020 Apr 28.
Multiple steps are needed to achieve the C-H functional of aromatic aldehyde, since the C-H functional reaction usually occurs preferentially at the aldehydic C-H bond over the aryl C-H bond. We report an efficient azidation method mediated by dirhodium(II) catalysts to achieve the direct aryl azidation of aromatic aldehydes avoiding the simultaneous use of protected aldehydes and prefunctionalized arenes. The regioselectivity of this method is similar to those of typical aromatic electrophilic substitution reactions. The resulting azidobenzaldehyde products are versatile building blocks or precursors for the synthesis of many biologically active compounds. The mechanism studies indicate that the one-electron oxidative intermediate Rh N is responsible for the azide transfer.
要实现芳香醛的 C-H 官能化，需要多个步骤，因为 C-H 官能化反应通常优先于醛基 C-H 键而发生于芳基 C-H 键。我们报道了一种由二钌(II)催化剂介导的有效叠氮化物方法，以实现芳香醛的直接芳基叠氮化，避免同时使用保护醛和预官能化芳烃。该方法的区域选择性类似于典型的芳香亲电取代反应。得到的叠氮苯甲醛产物是许多生物活性化合物合成的多功能构建块或前体。机理研究表明，单电子氧化中间体 Rh_N 负责叠氮化物转移。
