Cai Chen-Yan, Wu Zheng-Jian, Liu Ji-Ying, Chen Ming, Song Jinshuai, Xu Hai-Chao
Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China.
Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou, China.
Nat Commun. 2021 Jun 18;12(1):3745. doi: 10.1038/s41467-021-24125-5.
Oxidative allylic C-H functionalization is a powerful tool to streamline organic synthesis as it minimizes the need for functional group activation and generates alkenyl-substituted products amenable to further chemical modifications. The intramolecular variants can be used to construct functionalized ring structures but remain limited in scope and by their frequent requirement for noble metal catalysts and stoichiometric chemical oxidants. Here we report an oxidant-free, electrocatalytic approach to achieve intramolecular oxidative allylic C-H amination and alkylation by employing tailored cobalt-salen complexes as catalysts. These reactions proceed through a radical mechanism and display broad tolerance of functional groups and alkene substitution patterns, allowing efficient coupling of di-, tri- and even tetrasubstituted alkenes with N- and C-nucleophiles to furnish high-value heterocyclic and carbocyclic structures.
氧化烯丙基C-H官能化是简化有机合成的有力工具,因为它最大限度地减少了对官能团活化的需求,并生成适合进一步化学修饰的烯基取代产物。分子内变体可用于构建官能化的环状结构,但在范围上仍有局限性,并且经常需要贵金属催化剂和化学计量的化学氧化剂。在此,我们报告了一种无氧化剂的电催化方法,通过使用定制的钴-萨伦配合物作为催化剂来实现分子内氧化烯丙基C-H胺化和烷基化。这些反应通过自由基机理进行,对官能团和烯烃取代模式具有广泛的耐受性,允许二取代、三取代甚至四取代烯烃与N-和C-亲核试剂有效偶联,以提供高价值的杂环和碳环结构。