Wong Alexander S, Zhang Bufan, Li Bo, Neidig Michael L, Byers Jeffery A
Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States.
Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
Org Process Res Dev. 2021 Nov 19;25(11):2461-2472. doi: 10.1021/acs.oprd.1c00235. Epub 2021 Oct 12.
The development of an air-stable iron(III)-based precatalyst for the Suzuki-Miyaura cross-coupling reaction of alkyl halides and unactivated aryl boronic esters is reported. Despite benefits to cost and toxicity, the proclivity of iron(II)-based complexes to undergo deactivation oxidation or hydrolysis is a limiting factor for their widespread use in cross-coupling reactions compared to palladium-based or nickel-based complexes. The new octahedral iron(III) complex demonstrates long-term stability on the benchtop as assessed by a combination of H NMR spectroscopy, Mössbauer spectroscopy, and its sustained catalytic activity after exposure to air. The improved stability of the iron-based catalyst facilitates an improved protocol in which Suzuki-Miyaura cross-coupling reactions of valuable substrates can be assembled without the use of a glovebox and access a diverse scope of products similar to reactions assembled in the glovebox with iron(II)-based catalysts.
报道了一种用于卤代烃与未活化芳基硼酸酯的铃木-宫浦交叉偶联反应的空气稳定型铁（III）基预催化剂的开发。尽管铁（II）基配合物在成本和毒性方面具有优势，但与钯基或镍基配合物相比，其易于发生失活（氧化或水解）的倾向是其在交叉偶联反应中广泛应用的限制因素。通过核磁共振氢谱、穆斯堡尔谱以及其在暴露于空气后的持续催化活性评估，新的八面体铁（III）配合物在台面上表现出长期稳定性。铁基催化剂稳定性的提高促进了一种改进的方法，即无需使用手套箱就可以进行有价值底物的铃木-宫浦交叉偶联反应，并获得与在手套箱中使用铁（II）基催化剂进行的反应类似的多种产物。
