Nsouli Reem, Nayak Sneha, Balakrishnan Venkadesh, Lin Jung-Ying, Chi Benjamin K, Ford Hannah G, Tran Andrew V, Guzei Ilia A, Bacsa John, Armada Nicholas R, Zenov Fedor, Weix Daniel J, Ackerman-Biegasiewicz Laura K G
Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States.
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53716, United States.
J Am Chem Soc. 2024 Oct 30;146(43):29551-29559. doi: 10.1021/jacs.4c09621. Epub 2024 Oct 18.
Decarboxylative cross-coupling of carboxylic acids and aryl halides has become a key transformation in organic synthesis to form C(sp)-C(sp) bonds. In this report, a base metal pairing between Fe and Ni has been developed with complementary reactivity to the well-established Ir and Ni metallaphotoredox reactions. Utilizing an inexpensive FeCl cocatalyst along with a pyridine carboxamidine Ni catalyst, a range of aryl iodides can be preferentially coupled to carboxylic acids over boronic acid esters, triflates, chlorides, and even bromides in high yields. Additionally, carboxylic acid derivatives containing heterocycles, -protected amino acids, and protic functionality can be coupled in 23-96% yield with a range of sterically hindered, electron-rich, and electron-deficient aryl iodides. Preliminary catalytic and stoichiometric reactions support a mechanism in which Fe is responsible for the activation of carboxylic acid upon irradiation with light and a Ni alkyl intermediate is responsible for activation of the aryl iodide coupling partner followed by reductive elimination to generate product.
羧酸与芳基卤化物的脱羧交叉偶联已成为有机合成中形成C(sp)-C(sp)键的关键转化反应。在本报告中，已开发出铁和镍之间的贱金属配对，其反应活性与成熟的铱和镍金属光氧化还原反应互补。使用廉价的氯化亚铁助催化剂以及吡啶甲脒镍催化剂，一系列芳基碘化物可以优先与羧酸偶联，而不是硼酸酯、三氟甲磺酸酯、氯化物，甚至溴化物，产率很高。此外，含有杂环、受保护氨基酸和质子官能团的羧酸衍生物可以与一系列空间位阻大、富电子和缺电子的芳基碘化物以23-96%的产率偶联。初步的催化反应和化学计量反应支持一种机理，即铁负责在光照下活化羧酸，镍烷基中间体负责活化芳基碘化物偶联伙伴，随后通过还原消除生成产物。
