Chen Ming, Wu Zheng-Jian, Song Jinshuai, Xu Hai-Chao
State Key Laboratory of Physical Chemistry of Solid Surfaces, Innovative Collaboration Center of Chemistry for Energy Materials, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China.
Angew Chem Int Ed Engl. 2022 Mar 28;61(14):e202115954. doi: 10.1002/anie.202115954. Epub 2022 Feb 16.
The direct functionalization of allylic C-H bonds with nucleophiles minimizes pre-functionalization and converts inexpensive, abundantly available materials to value-added alkenyl-substituted products but remains challenging. Here we report an electrocatalytic allylic C-H alkylation reaction with carbon nucleophiles employing an easily available cobalt-salen complex as the molecular catalyst. These C(sp )-H/C(sp )-H cross-coupling reactions proceed through H evolution and require no external chemical oxidants. Importantly, the mild conditions and unique electrocatalytic radical process ensure excellent functional group tolerance and substrate compatibility with both linear and branched terminal alkenes. The synthetic utility of the electrochemical method is highlighted by its scalability (up to 200 mmol scale) under low loading of electrolyte (down to 0.05 equiv) and its successful application in the late-stage functionalization of complex structures.
烯丙基碳氢键与亲核试剂的直接官能团化可将预官能团化降至最低，并将价格低廉、易于获取的原料转化为高附加值的烯基取代产物，但仍然具有挑战性。在此，我们报道了一种用电化学方法实现的烯丙基碳氢键与碳亲核试剂的烷基化反应，该反应采用易于获得的钴-萨伦配合物作为分子催化剂。这些C(sp³)-H/C(sp²)-H交叉偶联反应通过析氢过程进行，无需外部化学氧化剂。重要的是，温和的反应条件和独特的电催化自由基过程确保了优异的官能团耐受性以及与直链和支链末端烯烃的底物兼容性。该电化学方法的合成实用性体现在其在低电解质负载量（低至0.05当量）下的可扩展性（高达200 mmol规模）以及在复杂结构后期官能团化中的成功应用。
