申请人:The Board of Trustees of the University of Illinois
公开号:US20190106448A1
公开(公告)日:2019-04-11
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 [Mn
III
(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 [Mn
III
(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.
直接将氮原子安装到复杂分子中的C-H键的反应具有重要意义,因为它们有可能改变给定化合物的化学和生物性质。实现高反应性,同时保持优秀的位点选择性和官能团耐受性的选择性分子内C-H胺化反应是一个具有挑战性的问题。本文报道了一种锰过氯酞菁催化剂[MnIII(ClPc)],用于分子间苄基C-H胺化反应,该反应在生物活性分子和天然产物中以前所未有的反应性和位点选择性进行。在Brønsted酸或Lewis酸的存在下,[MnIII(ClPc)]催化的C-H胺化展示了对叔胺、吡啶和苯并咪唑官能团的独特耐受性。机理研究表明,C-H胺化通过亲电金属亚硝烯中间体经过分步途径进行,其中C-H裂解是反应的速率决定步骤。总的来说,这些机理特征与之前基于贱金属催化的C-H胺化反应形成了对比。