Iron carbonyl complex containing bis[2-(diphenylphosphino)phenyi]ether enhancing efficiency in the paliadiym-cataiyzed Syzuki-Miyayra reaction

摘要

The reaction of [Fe3(CO)_(12)] with bis[2-(diphenylphosphino)phenyl1ether (DPEphos) in refluxing THF afforded a mononuclear complex, [Fe(C0)4(η~1-P-DPEphos)] (1), as major product and a binuclear complex, [Fe2(CO)6{|x-CO){|x-P,P-DPEphos)] (2), as minor product respectively. The DPEphos ligand acts as a terminal P-donor in complex 1 and a bridging P,P-donor in complex 2. Complexes 1 and 2 were characterized by elemental analysis, fast atom bombardment mass spectrometry, FT-IR, ~1H and ~(31)P {~1H} NMR spectroscopy. The structure of complex 1 has been tentatively assigned by density functional theory calculations and its analogy with reported complexes. Combination of complex 1 and PdCl2 furnished an active catalyst for the Suzuki-Miyaura cross-coupling reactions of various aryl halides with arylboronic acids. Interestingly, under the same experimental condition, complex l/PdCl2 as catalyst showed superior activity over the DPEphos/PdCl2 system.