Reactions that directly install nitrogen into C—H bonds of complex molecules are significant because of their potential to change the chemical and biological properties of a given compound. Selective intramolecular C—H amination reactions that achieve high levels of reactivity, while maintaining excellent site-selectivity and functional-group tolerance is a challenging problem. Herein is reported a manganese perchlorophthalocyanine catalyst [MnIII(ClPc)] for intermolecular benzylic C—H amination of bioactive molecules and natural products that proceeds with unprecedented levels of reactivity and site-selectivity. In the presence of Brønsted or Lewis acid, the [MnIII(ClPc)]-catalyzed C—H amination demonstrates unique tolerance for tertiary amine, pyridine and benzimidazole functionalities. Mechanistic studies indicate that C—H amination proceeds through an electrophilic metallonitrene intermediate via a stepwise pathway where C—H cleavage is the rate-determining step of the reaction. Collectively these mechanistic features contrast previous base-metal catalyzed C—H aminations. The catalyst can be a compound of Formula I:
在复杂分子的 C-H 键上直接安装氮的反应具有重要意义,因为它们有可能改变特定化合物的
化学和
生物特性。既能实现高
水平反应活性,又能保持良好的位点选择性和官能团耐受性的选择性分子内 C-H
氨化反应是一个具有挑战性的问题。本文报告了一种过
氯酞菁锰催化剂 [MnIII(ClPc)],用于
生物活性分子和
天然产物的分子间苄基 C-H
氨化反应,其反应活性和位点选择性达到了前所未有的
水平。在布氏酸或
路易斯酸存在的情况下,[MnIII(ClPc)]催化的 C-H amination 对叔胺、
吡啶和
苯并咪唑官能团具有独特的耐受性。机理研究表明,C-H
氨化反应是通过亲电茂
金属烯中间体逐步进行的,其中 C-H 裂解是反应的决定性步骤。这些机理特征与之前的碱
金属催化 C-H amination 形成了鲜明对比。催化剂可以是式 I 的化合物: