An iron(II) chloride complex possessing a sterically demanding ortho-phenylene-tethered bisphosphine ligand shows a high catalytic activity in the Kumada–Tamao–Corriu coupling of nonactivated alkyl halides with aryl Grignard reagents. Primary, secondary, and tertiary alkyl halides can participate as an electrophilic coupling partner. A radical clock experiment using (iodomethyl)cyclopropane exclusively gives the corresponding ring-opening coupling product, suggesting intermediacy of alkyl radical species.
在非活化烷基卤化物与芳基
格氏试剂的 Kumada-Tamao-Corriu 偶联反应中,一种具有立体要求高的邻苯系双
膦配体的
氯化
铁(II)配合物显示出很高的催化活性。伯、仲和叔烷基卤化物都可以作为亲电
偶联剂参与偶联。使用(
碘甲基)
环丙烷进行的自由基时钟实验只得到了相应的开环偶联产物,这表明烷基自由基物种具有中间性。