1258941-84-2Relevant academic research and scientific papers
Planar chiral P,O-compounds derived from ferrocenyl aryl ethers
Schaarschmidt, Dieter,Lang, Heinrich
, p. 4811 - 4821 (2011/03/01)
The ortho-directed lithiation of FcOC6H4-4-tBu (1) [Fc = (η5-C5H4)(η5-C 5H5)Fe] with nBuLi/tmeda is reported (tmeda = tetramethylethylenediamine). In this reaction, multimetalation occurs to yield novel 1,2-functionalized P,O-derivatives that contain up to four phosphanyl moieties as determined by NMR spectroscopic studies and single-crystal X-ray diffraction analysis. Thus available planar chiral P,O-ferrocenes can successfully be applied in the palladium-catalyzed Suzuki coupling of diverse aryl halides and aryl boronic acids. The aforementioned systems allow the activation of carbon-chlorine bonds in an efficient way and tolerate catalyst loadings as low as 10 ppm. Noteworthy is their remarkable ability to economically generate hindered biaryls under mild reaction conditions. Planar chiral P,O-ferrocenes are excellent ligands in the palladium-mediated C-C coupling of aryl halides and aryl boronic acids. They allow either the conversion ofunreactive substrates or reactions to be performed at low catalyst levels. Moreover, multiply ortho-substituted biaryls are accessible under mild conditions.
